| 1. |
- Savvidou, Antri, et al.
(författare)
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Novel imaging findings in pyruvate dehydrogenase complex (PDHc) deficiency—Results from a nationwide population-based study
- 2022
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Ingår i: Journal of Inherited Metabolic Disease. - : Wiley. - 0141-8955 .- 1573-2665. ; 45:2, s. 248-263
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Tidskriftsartikel (refereegranskat)abstract
- The vast clinical and radiological spectrum of pyruvate dehydrogenase complex (PDHc) deficiency continues to pose challenges both in diagnostics and disease monitoring. Prompt diagnosis is important to enable early initiation of ketogenic diet. The patients were recruited from an ongoing population-based study in Sweden. All patients with a genetically confirmed diagnosis who had been investigated with an MRI of the brain were included. Repeated investigations were assessed to study the evolution of the MRI changes. Sixty-two MRI investigations had been performed in 34 patients (23 females). The genetic cause was mutations in PDHA1 in 29, PDHX and DLAT in 2 each, and PDHB in 1. The lesions were prenatal developmental in 16, prenatal clastic in 18, and postnatal clastic in 15 individuals. Leigh-like lesions with predominant involvement of globus pallidus were present in 12, while leukoencephalopathy was present in 6 and stroke-like lesions in 3 individuals. A combination of prenatal developmental and clastic lesions was present in 15 individuals. In addition, one male with PDHA1 also had postnatal clastic lesions. The most common lesions found in our study were agenesis or hypoplasia of corpus callosum, ventriculomegaly, or Leigh-like lesions. Furthermore, we describe a broad spectrum of other MRI changes that include leukoencephalopathy and stroke-like lesions. We argue that a novel important clue, suggesting the possibility of PDHc deficiency on MRI scans, is the simultaneous presence of multiple lesions on MRI that have occurred during different phases of brain development.
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| 2. |
- Sofou, Kalliopi, et al.
(författare)
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Cerebrospinal fluid neurofilament light is associated with survival in mitochondrial disease patients
- 2019
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Ingår i: Mitochondrion. - : Elsevier BV. - 1567-7249 .- 1872-8278. ; 46, s. 228-235
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Tidskriftsartikel (refereegranskat)abstract
- We studied the biomarker patterns related to axonal injury, astrogliosis and amyloid metabolism in cerebrospinal fluid (CSF) of children and adolescents with mitochondrial encephalopathy and identified correlations with phenotype and survival outcome. Forty-six pediatric patients with genetically verified mitochondrial encephalopathy and twenty-two controls investigated at the Queen Silvia Children's Hospital, Sweden, were included. CSF lactate and neurofilament light (NF-L) were significantly increased in patients with mitochondrial encephalopathy compared to controls. Elevated CSF NF-L was associated with abnormal brain MRI and poorer survival. We suggest that CSF NF-L may be used in both clinical and research settings for monitoring the neurodegenerative process in mitochondrial disease.
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| 3. |
- Szakacs, Attila, et al.
(författare)
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A population-based and case-controlled study of children and adolescents with narcolepsy: Health-related quality of life, adaptive behavior and parental stress
- 2019
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Ingår i: European Journal of Paediatric Neurology. - : Elsevier BV. - 1090-3798. ; 23:2, s. 288-295
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate health-related quality of life (HrQoL) and adaptive behavior in young people with narcolepsy and stress among their parents. Methods: In a cross-sectional exploratory quantitative study design, 37 young people with narcolepsy (8-20 years of age) and their parents were recruited. Thirty-one had post-H1N1 vaccination-related narcolepsy (PHV) and six had narcolepsy not related to PHV (nPHV). In addition, 40 age- and gender-matched controls (aged 5-20 years) were recruited. Results: Thirty-one patients completed the generic HrQoL questionnaire KIDSCREEN and the disease-specific NARQoL-21. HrQoL was found to be significantly diminished in all domains in the PHV group (p = 0.001) and in the School/Concentration domain (p = 0.004) in the nPHV group compared to age- and gender-matched controls. The Adaptive Behavior Assessment System was completed by parents of 32 patients. They rated their children significantly lower in the General adaptive composite (p = 0.026) and the Conceptual (p = 0.050) and Social composite scores (p = 0.001) compared with reference data on healthy Swedish children's and young people's adaptive behavior. Parents of 36 patients filled in the 36-item short form of the Parenting Stress Index questionnaire. They rated significantly higher Total stress, Parent-child dysfunctional interaction, and Difficult child scores compared with parents of controls (p = 0.001, p = 0.005, p < 0.001). Conclusions: Children with narcolepsy have diminished HrQoL compared with controls. Parents of children with narcolepsy experience impaired adaptive behavior in their children and high levels of parenting stress. Identifying the contributory factors is necessary, and early intervention is crucial in order to improve the HrQoL of these children and their families. (C) 2019 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.
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| 4. |
- Szakacs, Attila, et al.
(författare)
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Endocrine and metabolic aspects of narcolepsy type 1 in children
- 2021
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Ingår i: European Journal of Paediatric Neurology. - : Elsevier BV. - 1090-3798. ; 33, s. 68-74
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Tidskriftsartikel (refereegranskat)abstract
- Study objectives: To study whether the onset of narcolepsy type 1 (NT1) in children and adolescents affects BMI, specific metabolic risk factors, the onset of puberty, longitudinal growth or other endocrine functions. Methods: A population-based study, comprising 34 patients, was performed with a clinical evaluation, an assessment of puberty and growth, actigraphy and blood samples at fasting, from patients and controls, to evaluate pituitary function, growth factors, thyroid gland, gonads, insulin sensitivity, appetite regulation and blood lipids. Results: In the post-H1N1 vaccination (PHV) narcolepsy group, the median BMI SDS was higher 6-12 months after the onset of narcolepsy (p < 0.01), but it was no different 10 years after the onset of narcolepsy (p = 0.91), compared with 12-24 months before the onset of narcolepsy. There was a correlation between an increase in BMI and a decrease in total energy expenditure (R =-0.74). In the nPHV group, weight and BMI changes were smaller and no significant changes were recorded. Early puberty was more common in patients with puberty onset after narcolepsy onset (n = 16/19) compared with patients with puberty onset before narcolepsy onset (n = 3/11, p = 0.02). There was no significant change in height SDS during the studied period. Although they were within normal ranges, both median HDL and median TSH levels were significantly lower in NT1 patients, compared with controls. Conclusions: We found a high prevalence of large BMI gain in the period immediately after the onset of narcolepsy, which had almost normalized at the long-term follow-up. The onset of narcolepsy led to early puberty in both sexes. Linear growth was not affected. We did not find any strong indicators of metabolic disturbances. (c) 2021 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.
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| 5. |
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| 6. |
- Örlén, Hanna, et al.
(författare)
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SPG11 mutations cause Kjellin syndrome, a hereditary spastic paraplegia with thin corpus callosum and central retinal degeneration.
- 2009
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Ingår i: American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics. - : Wiley. - 1552-485X .- 1552-4841. ; 150B:7, s. 984-992
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Tidskriftsartikel (refereegranskat)abstract
- Autosomal recessive hereditary spastic paraplegia (ARHSP) with thin corpus callosum (TCC) is genetically heterogenous and approximately 35% of patients carry mutations in either of the SPG11 or SPG15 genes. Disease onset is during the first three decades of life with spastic paraplegia and mental impairment. Peripheral neuropathy and amyotrophy may occur. Kjellin syndrome is characterized by central retinal degeneration in addition to ARHSP-TCC and the disease is associated with mutations in the SPG15 gene. We identified five patients in four unrelated kindreds with spastic paraplegia and mental impairment. Magnetic resonance imaging revealed TCC, atrophy elsewhere in the brain and increased T2 signal intensity in the periventricular white matter. Probands from the four kindreds were screened for mutations in the SPG11 gene. All patients were found homozygous or compound heterozygous for truncating SPG11 mutations of which four are reported for the first time. Ophthalmological investigations revealed that the four index cases have central retinal degeneration consistent with Kjellin syndrome. PET examinations with N-[11C-methyl]-L-deuterodeprenyl (DED) and fluor-18 2-fluorodeoxyglucose (FDG) were performed in two patients with Kjellin syndrome. We observed a reduced glucose uptake in the thalami, anterior cingulum, and sensorimotor cortex indicating neuronal loss, and an increased DED binding in the thalami and pons which suggests astrogliosis. From our results we extend the SPG11 associated phenotype to comprise also Kjellin syndrome, previously found to be associated with mutations in the SPG15 gene. We anticipate that degeneration of the central retina is a common and previously unrecognized feature in SPG11 related disease.
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| 7. |
- Andersson Grönlund, Marita, 1959-, et al.
(författare)
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Ophthalmological findings in children and young adults with genetically verified mitochondrial disease
- 2010
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Ingår i: British Journal of Ophthalmology. - : BMJ Publishing Group Ltd. - 0007-1161 .- 1468-2079. ; 94:1, s. 121-127
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To describe ophthalmological phenotypes in patients with mitochondrial disease and known genotypes.METHODS: A retrospective study was performed on 59 patients (29 male, 30 female) with a mean age of 11.8 years who had mitochondrial disease with known DNA mutations. Fifty-seven of the 59 subjects underwent a detailed ophthalmological examination including visual acuity (VA), eye motility, refraction, slit-lamp examination, ophthalmoscopy and, in almost one-half of the cases, a full-field electroretinogram (ERG).RESULTS: Forty-six (81%) of the patients had one or more ophthalmological findings such as ptosis (n = 16), reduced eye motility (n = 22) including severe external ophthalmoplegia (n = 9), strabismus (n = 4), nystagmus (n = 9), low VA (n = 21), refractive errors (n = 26), photophobia (n = 4), and partial or total optic atrophy (n = 25). Pigmentation in the macula and/or periphery was noted in 16 patients. In 10/27 investigated individuals with full field ERG, retinal dystrophy was recorded in six different genotypes representing Kearns-Sayre syndrome (n = 5), Leigh syndrome (n = 1), Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) (n = 1), Myoclonus epilepsy with red ragged fibres (MERRF) (n = 1), Leber hereditary optic neuropathy (n = 1) and mitochondrial myopathy (n = 1).CONCLUSION: The results show that a majority of patients with mitochondrial disorders have ophthalmological abnormalities. We recommend that an ophthalmological examination, including ERG, be performed on all children and adolescents who are suspected of having a mitochondrial disease.
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| 8. |
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| 9. |
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| 10. |
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| 11. |
- Arkblad, Eva L, et al.
(författare)
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Multiplex ligation-dependent probe amplification improves diagnostics in spinal muscular atrophy
- 2006
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Ingår i: Neuromuscular disorders : NMD. - : Elsevier BV. - 0960-8966 .- 1873-2364. ; 16:12, s. 830-8
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Tidskriftsartikel (refereegranskat)abstract
- Spinal muscular atrophy (SMA) is an autosomal recessive disease caused by decreased levels of survival motor neuron protein (SMN). In the majority of cases, this decrease is due to absence of the SMN1 gene. Multiplex ligation-dependent probe amplification (MLPA) is a modern quantitative molecular method. Applied in SMA cases, it improves diagnostics by simultaneously identifying the number of copies of several target sequences in the SMN1 gene and in nearby genes. Using MLPA in clinical diagnostics, we have identified a previously unreported, partial deletion of SMN1 (exons 1-6) in two apparently unrelated Swedish families. This mutation would not have been detected by conventional diagnostic methods. This paper illustrates the broad clinical and genetic spectrum of SMA and includes reports of MLPA results and clinical descriptions of a patient with homozygous absence of SMN1 and only one SMN2 (prenatal onset SMA type 1), an asymptomatic woman with five SMN2 (lacking SMN1) and representative patients with SMA types 1, 2 and 3.
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| 12. |
- Björkman, Kristoffer, et al.
(författare)
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Broad phenotypic variability in patients with complex I deficiency due to mutations in NDUFS1 and NDUFV1.
- 2015
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Ingår i: Mitochondrion. - : Elsevier BV. - 1872-8278 .- 1567-7249. ; 21, s. 33-40
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Tidskriftsartikel (refereegranskat)abstract
- We report clinical, metabolic, genetic and neuroradiological findings in five patients from three different families with isolated complex I deficiency. Genetic analysis revealed mutations in NDUFS1 in three patients and in NDUFV1 in two patients. Four of the mutations are novel and affect amino acid residues that either are invariant among species or conserved in their properties. The presented clinical courses are characterized by leukoencephalopathy or early death and expand the already heterogeneous phenotypic spectrum. A literature review was performed, showing that patients with mutations in NDUFS1 in general have a worse prognosis than patients with mutations in NDUFV1.
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| 13. |
- Björkman, Kristoffer, et al.
(författare)
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Clinical course of patients with single large-scale mtDNA deletions and childhood onset anemia
- 2022
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Ingår i: 14th European Paediatric Neurology Society Congress, Glasgow, UK (ISBN 978-3-00-072065-9).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Objective: To add to our knowledge of the clinical spectrum of patients with single large-scale mitochondrial DNA (mtDNA) deletion and childhood onset anemia. Methods: Retrospective collection of clinical data from medical records for patients, both living and deceased, with a single large-scale mtDNA deletion from seven mitochondrial disease centers in five countries. Statistical analysis with descriptive methods and Kaplan-Meier survival analysis. Results: Seventeen patients matching the genetic criterium and with anemia onset before six years of age. Exocrine pancreatic insufficiency was only seen in five patients in this group. Multiple organs were involved in all patients, with the most common non-hematologic ones being skeletal muscle, central nervous system, endocrine, eyes, gastrointestinal system, kidneys, hearing, liver and heart. Psychomotor retardation was seen in ten patients, hearing impairment in nine patients, failure to thrive in eight patients. Eight later developed Kearns-Sayre syndrome. Eleven patients were deceased, with a median age at death of 7.5 years. Conclusions: The classically described phenotype of patients with large-scale mtDNA deletions and early onset anemia is Pearson marrow-pancreas syndrome, characterized by sideroblastic anemia and exocrine pancreas dysfunction. Only a minority of our patients fulfill the original criteria of Pearson syndrome though. Involvement of other organs than the pancreas is more common. The clinical course vary, but multi-system impact is the rule and life-expectancy is low. Early onset anemia in patients with large-scale mtDNA deletions is most frequently not associated with exocrine pancreas dysfunction. Better knowledge of the phenotype is helpful for diagnosis and more accurate prognosis.
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| 14. |
- Björkman, Kristoffer, et al.
(författare)
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Genotype-phenotype correlations in patients with complex I deficiency due to mutations in NDUFS1 and NDUFV1
- 2014
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Ingår i: Euromit 2014, 15-19 juni, Tampere, Finland.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Objectives: To study genotype-phenotype correlations in genes encoding complex I electron input module subunits. Materials and methods: We studied five patients with isolated complex I deficiency, three with NDUFS1 mutations and two with NDUFV1 mutations. A literature review of all reported cases of mutations in the affected genes was performed. Results: The literature review revealed pathological mutations in NDUFS1 for 18 patients in 17 families and correspondingly in NDUFV1 for 26 patients in 19 families. Unpublished clinical data for our five patients were added. Our study showed quite variable clinical courses; death before two years of age was seen in 41% of patients while 18% were alive at seven years. There was a significant difference between the NDUFS1 and NDUFV1 groups for clinical onset and life-span. Mutations in NDUFS1 were linked to a worse clinical course with earlier onset and earlier death. Conclusions: Genotype-phenotype correlations in patients with mutations affecting the genes that encode the electron input module of complex I vary, but patients with NDUFS1 mutation tend to have a worse clinical course than patients with NDUFV1 mutation. Identifying the mutations is of importance for accurate prognostic information and genetic counseling.
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| 15. |
- Björkman, Kristoffer, et al.
(författare)
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Phenotypic spectrum and clinical course of single large-scale mitochondrial DNA deletion disease in the paediatric population: a multicentre study.
- 2021
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Ingår i: Journal of Medical Genetics. - : BMJ. - 0022-2593 .- 1468-6244. ; 60:1, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- Background Large-scale mitochondrial DNA deletions (LMD) are a common genetic cause of mitochondrial disease and give rise to a wide range of clinical features. Lack of longitudinal data means the natural history remains unclear. This study was undertaken to describe the clinical spectrum in a large cohort of patients with paediatric disease onset. Methods A retrospective multicentre study was performed in patients with clinical onset <16 years of age, diagnosed and followed in seven European mitochondrial disease centres. Results A total of 80 patients were included. The average age at disease onset and at last examination was 10 and 31 years, respectively. The median time from disease onset to death was 11.5 years. Pearson syndrome was present in 21%, Kearns-Sayre syndrome spectrum disorder in 50% and progressive external ophthalmoplegia in 29% of patients. Haematological abnormalities were the hallmark of the disease in preschool children, while the most common presentations in older patients were ptosis and external ophthalmoplegia. Skeletal muscle involvement was found in 65% and exercise intolerance in 25% of the patients. Central nervous system involvement was frequent, with variable presence of ataxia (40%), cognitive involvement (36%) and stroke-like episodes (9%). Other common features were pigmentary retinopathy (46%), short stature (42%), hearing impairment (39%), cardiac disease (39%), diabetes mellitus (25%) and renal disease (19%). Conclusion Our study provides new insights into the phenotypic spectrum of childhood-onset, LMD-associated syndromes. We found a wider spectrum of more prevalent multisystem involvement compared with previous studies, most likely related to a longer time of follow-up.
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| 16. |
- Bomfim, I L, et al.
(författare)
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The immunogenetics of narcolepsy associated with A(H1N1)pdm09 vaccination (Pandemrix) supports a potent gene-environment interaction.
- 2017
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Ingår i: Genes and immunity. - : Springer Science and Business Media LLC. - 1476-5470 .- 1466-4879. ; 18, s. 75-81
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Tidskriftsartikel (refereegranskat)abstract
- The influenza A(H1N1)pdm09 vaccination campaign from 2009 to 2010 was associated with a sudden increase in the incidence of narcolepsy in several countries. Narcolepsy with cataplexy is strongly associated with the human leukocyte antigen (HLA) class II DQB1*06:02 allele, and protective associations with the DQB1*06:03 allele have been reported. Several non-HLA gene loci are also associated, such as common variants of the T-cell receptor-α (TRA), the purinergic receptor P2RY11, cathepsin H (CTSH) and TNFSF4/OX40L/CD252. In this retrospective multicenter study, we investigated if these predisposing gene loci were also involved in vaccination-associated narcolepsy. We compared HLA- along with single-nucleotide polymorphism genotypes for non-HLA regions between 42 Pandemrix-vaccinated narcolepsy cases and 1990 population-based controls. The class II gene loci associations supported previous findings. Nominal association (P-value<0.05) with TRA as well as suggestive (P-value<0.1) associations with P2RY11 and CTSH were found. These associations suggest a very strong gene-environment interaction, in which the influenza A(H1N1)pdm09 strain or Pandemrix vaccine can act as potent environmental triggers.Genes and Immunity advance online publication, 23 March 2017; doi:10.1038/gene.2017.1.
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| 17. |
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| 18. |
- Chaplin, John, 1955, et al.
(författare)
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The development of a health-related quality-of-life instrument for young people with narcolepsy: NARQoL-21
- 2017
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Ingår i: Health and Quality of Life Outcomes. - : Springer Science and Business Media LLC. - 1477-7525. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Narcolepsy is a lifelong sleep disorder with a prevalence of between 0.03% and 0.06% and onset at around puberty. It is associated with psychiatric comorbidities and cognitive difficulties. No valid and reliable condition-specific health-related quality-of-life (HrQoL) instrument has been developed for this population. METHODS: A questionnaire based on four mixed-gender age-defined focus group discussions and a patient panel analysis was administered to young people with narcolepsy and a control group. External reliability was measured by a test-retest procedure and internal reliability was measured using Cronbach's alpha. Convergent validity with the KIDSCREEN-10 index was assessed using with intraclass correlation coefficients (ICC) and receiver operating characteristic (ROC) curves. Factor analysis techniques were used to identify suitable items and confirm the factor structure. Baseline values were assessed for convergent validity, ceiling effects, agreement and sensitivity. Comparison with KIDSCREEN-10 was made on the basis of area under the curve (AUC). RESULTS: One hundred young people with narcolepsy and 95 control subjects returned questionnaires. The factor structure revealed two main factors with five domains and 21 questions, which was confirmed with confirmatory factor analysis. The domains of the NARQoL-21 showed good independence while the floor and ceiling effects were acceptable. The external reliability (0.928), convergent validity (rs = 0.769) and internal consistency (Cronbach's alpha = 0.886) were excellent. A Bland-Altman plot revealed some proportional bias. Good discriminant validity was detected for control/patient (Cohen's d = 2.114). ROC analysis showed significantly better AUC for NARQoL-21 (0.939) than KIDSCREEN (0.877). A cut-off score equivalent to KIDSCREEN-10 for suboptimal HrQoL which maximized sensitivity (84%) and specificity (92%) was found at NARQoL-21 score below 42. CONCLUSIONS: Establishing the validity of a disease-specific HrQoL instrument in a population of people with a rare condition poses significant challenges. The mixed-methods approach adopted here has resulted in a questionnaire of 21 items with good discrimination and convergent validity, and excellent internal and external reliability, allowing precise and stable measurements. The cut-off score can be useful to identify patients with very poor HrQoL and thus improve the design of treatment options. Further testing in a longitudinal cohort is recommended in order to establish responsiveness.
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| 19. |
- Darin, Niklas, 1964, et al.
(författare)
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3-methylcrotonyl-CoA carboxylase deficiency and severe multiple sclerosis.
- 2007
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Ingår i: Pediatric neurology. - : Elsevier BV. - 0887-8994. ; 36:2, s. 132-4
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Tidskriftsartikel (refereegranskat)abstract
- This report describes a female with isolated 3-methylcrotonyl-CoA carboxylase deficiency. She had a mild Reye-like episode, loss of scalp hair, psychomotor retardation, and an attention-deficit hyperactivity disorder. The diagnosis was made at 13 years of age when she developed relapsing remitting multiple sclerosis with a malignant course. Treatment with steroids had initially a good therapeutic effect on the relapses. The response to interferon beta-1a treatment was poor. On mitoxantrone treatment there was a considerable neurologic recovery.
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| 20. |
- Darin, Niklas, 1964, et al.
(författare)
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Benign mitochondrial myopathy with exercise intolerance in a large multigeneration family due to a homoplasmic m.3250T>C mutation in MTTL1.
- 2017
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Ingår i: European journal of neurology. - : Wiley. - 1468-1331 .- 1351-5101. ; 24:4, s. 587-593
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Tidskriftsartikel (refereegranskat)abstract
- Most mitochondrial disorders with onset in early childhood are progressive and involve multiple organs. The m.3250T>C mutation in MTTL1 has previously been described in a few individuals with a possibly riboflavin-responsive myopathy and an association with sudden infant death syndrome was suspected. We describe a large family with this mutation and evaluate the effect of riboflavin treatment.Medical data were collected with the help of a standardized data collection form. Sanger sequencing was used to screen for variants in mitochondrial DNA and the proportion of the mutation was analyzed in different tissues. Biochemical and muscle morphological investigations of muscle tissue were performed in two individuals. The effect of riboflavin treatment was evaluated in two individuals.Thirteen family members experienced exercise intolerance with fatigue and weakness. Inheritance was maternal with 100% penetrance. The course was either static or showed improvement over time. There was no evidence of other organ involvement except for a possible mild transient cardiac enlargement in one child. Muscle investigations showed isolated complex I deficiency and mitochondrial proliferation. The level of m.3250T>C was apparently 100%, i.e. homoplasmic, in all examined tissues. Riboflavin treatment showed no effect in any treated family member and there have been no cases of sudden infant death in this family.This study illustrates the importance of considering mitochondrial disorders in the work-up of individuals with exercise intolerance and provides a better understanding of the phenotype associated with the m.3250T>C mutation in MTTL1.
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| 21. |
- Darin, Niklas, 1964, et al.
(författare)
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Changes in prevalence, aetiology, age at detection, and associated disabilities in preschool children with hearing impairment born in Göteborg.
- 1997
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Ingår i: Developmental medicine and child neurology. - : Wiley. - 0012-1622 .- 1469-8749. ; 39:12, s. 797-802
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of hearing impairment (HI) in preschool children born in Göteborg in 1980 to 1984 was 2.0 per 1000. This was significantly lower than the 3.8 per 1000 found in a previous study for 1970 to 1974. The decrease took place in the moderate to severe range of HI, while deafness and mild HI remained unchanged during the period. The cause was considered to be prenatal in 58% with heredity in 33% as the main causative factor. Following the introduction of the MPR (Morbilli-Parotitis-Rubella) vaccination programme in Sweden, no cases of rubella- or mumps-induced HI could be found. The number of HI of perinatal origin decreased by half, in spite of the fact that the figures for preterm baby survival almost doubled during the period. Associated disabilities were diagnosed in 62% of the children with HI; speech retardation in 33%, visual abnormalities in 30%, mental retardation in 12% and neuropsychiatric disorders in 9% of the cases. The importance of collaborative efforts between the otolaryngologist and the neurologically and neuropsychiatrically interested paediatrician in the complete evaluation of additional difficulties in the HI child is emphasized.
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| 22. |
- Darin, Niklas, 1964, et al.
(författare)
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Clinical, serological and PCR evidence of cytomegalovirus infection in the central nervous system in infancy and childhood.
- 1994
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Ingår i: Neuropediatrics. - : Georg Thieme Verlag KG. - 0174-304X .- 1439-1899. ; 25:6, s. 316-22
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Tidskriftsartikel (refereegranskat)abstract
- Over a 3-year-period (Dec. 1990-Nov. 1993) 12 children were found PCR-positive for CMV-DNA in CSF and brain biopsies. Three of the patients were immunologically compromised. During the same period CSF samples from 10 shunt-operated children and 143 virological routine CSF samples were PCR CMV negative. Clinical association with positive PCR-CMV reaction was considered likely in 6 patients: two boys developed prolonged fever and meningoencephalitis following neurosurgery, one infant girl had a course compatible with congenital inclusion disease, and three had prolonged fever following transplantation. Clinical association was deemed probable in 3 infant girls: one had neonatal infection, meningitis and intraventricular haemorrhage, one had neonatal encephalitis and failure to thrive, and one with neonatal seizures and encephalitis developed brain atrophy. Clinical association was judged possible in 3 patients: one infant girl with no signs of encephalitis developed brain atrophy, one had an Aicardi Type 1 syndrome and one 2 1/2-year-old boy had an acute encephalitis with insufficient serological support for CMV but was 12 months later PCR positive for CMV. We conclude that CMV may be an overlooked infectious agent of the CNS also in immunocompetent children. PCR aids in rapid diagnosis of CMV infection in the immunocompromised. CMV may occasionally be disclosed with PCR in other conditions as a probably non-relevant observation.
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| 23. |
- Darin, Niklas, 1964, et al.
(författare)
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Fortskridande hjärnsjukdomar
- 2012
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Ingår i: Barnmedicin, (red) K.Hanseus, H.Lagercrantz, T. Lindberg.. - Lund : Studentlitteratur. - 9789144076096 ; , s. 419-424
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 24. |
- Darin, Niklas, 1964, et al.
(författare)
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Functional analysis of a novel POL gamma A mutation associated with a severe perinatal mitochondrial encephalomyopathy
- 2021
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Ingår i: Neuromuscular Disorders. - : Elsevier BV. - 0960-8966. ; 31:4, s. 348-358
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in the mitochondrial DNA polymerase gamma catalytic subunit (POL. A) compromise the stability of mitochondrial DNA (mtDNA) by leading to mutations, deletions and depletions in mtDNA. Patients with mutations in POL gamma A often differ remarkably in disease severity and age of onset. In this work we have studied the functional consequence of POL gamma A mutations in a patient with an uncommon and a very severe disease phenotype characterized by prenatal onset with intrauterine growth restriction, lactic acidosis from birth, encephalopathy, hepatopathy, myopathy, and early death. Muscle biopsy identified scattered COX-deficient muscle fibers, respiratory chain dysfunction and mtDNA depletion. We identified a novel POL.A mutation (p.His1134Tyr) in trans with the previously identified p.Thr251Ile/Pro587Leu double mutant. Biochemical characterization of the purified recombinant POL gamma A variants showed that the p.His1134Tyr mutation caused severe polymerase dysfunction. The p.Thr251Ile/Pro587Leu mutation caused reduced polymerase function in conditions of low dNTP concentration that mimic postmitotic tissues. Critically, when p.His1134Tyr and p.Thr251Ile/Pro587Leu were combined under these conditions, mtDNA replication was severely diminished and featured prominent stalling. Our data provide a molecular explanation for the patients mtDNA depletion and clinical features, particularly in tissues such as brain and muscle that have low dNTP concentration. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
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| 25. |
- Darin, Niklas, 1964, et al.
(författare)
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Inflammation and response to steroid treatment in limb-girdle muscular dystrophy 2I
- 2007
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Ingår i: Eur J Paediatr Neurol. - : Elsevier BV. ; 11:6, s. 353-7
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Tidskriftsartikel (refereegranskat)abstract
- Limb-girdle muscular dystrophy (LGMD) type 2I, caused by mutations in the fukutin-related protein gene (FKRP), is one of the most common forms of LGMD in childhood. We describe two patients with LGMD2I and a Duchenne-like phenotype. In addition to the common L276I mutation, both patients had a new mutation in FKRP, L169P and P89L, respectively. Clinical onset was triggered by viral upper respiratory tract infections. In addition to the common dystrophic pattern with a weak immune histochemical staining for alpha-dystroglycan, muscle biopsy showed inflammatory changes. This was especially striking in one of the patients with up-regulation of MHC class 1 antigen, suggestive of myositis. Both patients showed a good clinical response to treatment with prednisolone, which was initiated at daily dosage of 0.35mg/kg/day. Our results provide evidence for an inflammatory involvement in the pathological expression of LGMD2I and open up the possibility that this disorder could be treatable with corticosteroids.
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| 26. |
- Darin, Niklas, 1964, et al.
(författare)
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Mitochondrial myopathy with exercise intolerance and retinal dystrophy in a sporadic patient with a G583A mutation in the mt tRNA(phe) gene
- 2006
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Ingår i: Neuromuscular disorders : NMD. - : Elsevier BV. - 0960-8966 .- 1873-2364. ; 16:8, s. 504-6
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Tidskriftsartikel (refereegranskat)abstract
- We describe a second patient with the 583G>A mutation in the tRNA(phe) gene of mitochondrial DNA (mtDNA). This 17-year-old girl had a mitochondrial myopathy with exercise intolerance and an asymptomatic retinopathy. Muscle investigations showed occasional ragged red fibers, 30% cytochrome c oxidase (COX)-negative fibers, and reduced activities of complex I+IV in the respiratory chain. The mutation was heteroplasmic (79%) in muscle but undetectable in other tissues. Analysis of single muscle fibers revealed a significantly higher level of mutated mtDNA in COX-negative fibers. Our study indicates that the 583G>A mutation is pathogenic and expands the clinical spectrum of this mutation.
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| 27. |
- Darin, Niklas, 1964, et al.
(författare)
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Mutations in PROSC Disrupt Cellular Pyridoxal Phosphate Homeostasis and Cause Vitamin-B6-Dependent Epilepsy.
- 2016
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Ingår i: American journal of human genetics. - : Elsevier BV. - 1537-6605 .- 0002-9297. ; 99:6, s. 1325-1337
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Tidskriftsartikel (refereegranskat)abstract
- Pyridoxal 5'-phosphate (PLP), the active form of vitamin B6, functions as a cofactor in humans for more than 140 enzymes, many of which are involved in neurotransmitter synthesis and degradation. A deficiency of PLP can present, therefore, as seizures and other symptoms that are treatable with PLP and/or pyridoxine. Deficiency of PLP in the brain can be caused by inborn errors affecting B6 vitamer metabolism or by inactivation of PLP, which can occur when compounds accumulate as a result of inborn errors of other pathways or when small molecules are ingested. Whole-exome sequencing of two children from a consanguineous family with pyridoxine-dependent epilepsy revealed a homozygous nonsense mutation in proline synthetase co-transcribed homolog (bacterial), PROSC, which encodes a PLP-binding protein of hitherto unknown function. Subsequent sequencing of 29 unrelated indivduals with pyridoxine-responsive epilepsy identified four additional children with biallelic PROSC mutations. Pre-treatment cerebrospinal fluid samples showed low PLP concentrations and evidence of reduced activity of PLP-dependent enzymes. However, cultured fibroblasts showed excessive PLP accumulation. An E.coli mutant lacking the PROSC homolog (ΔYggS) is pyridoxine sensitive; complementation with human PROSC restored growth whereas hPROSC encoding p.Leu175Pro, p.Arg241Gln, and p.Ser78Ter did not. PLP, a highly reactive aldehyde, poses a problem for cells, which is how to supply enough PLP for apoenzymes while maintaining free PLP concentrations low enough to avoid unwanted reactions with other important cellular nucleophiles. Although the mechanism involved is not fully understood, our studies suggest that PROSC is involved in intracellular homeostatic regulation of PLP, supplying this cofactor to apoenzymes while minimizing any toxic side reactions.
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| 28. |
- Darin, Niklas, 1964
(författare)
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Neuromuscular disorders in childhood. Epidemiology and characterization of a new myopathy
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Neuromuscular disorders can be subdivided into anterior horn cell disorders, neuropathies, myasthenic disorders and myopathies. Some multisystem disorders, such as myotonic dystrophy and mitochondrial encephalomyopathies, are traditionally also included. The frequency in childhood of these disorders in general and of mitochondrial encephalomyopathies in particular is not well known. The purpose of this study was to perform an epidemiologic survey of neuromuscular disorders in children < 16 years of age from western Sweden. Cases were ascertained from different registers and medical records, investigations and diagnoses were reviewed in order to determine prevalence and incidence figures. A population-based study was conducted to describe the preschool incidence, point prevalence, mortality and the clinical spectrum of mitochondrial encephalomyopathies in childhood. In addition, a large family with a new type of congenital myopathy was investigated to characterize the clinical, muscle morphologic and genetic features of the disorder. In children of school age (6-15 years) the point prevalence was 79.8 x 10-5 for all neuromuscular disorders, 66.5 x 10-5 for hereditary neuromuscular disorders and 19.9 x 10-5 for hereditary motor and sensory neuropathies. The incidences of Duchenne muscular dystrophy, spinal muscular atrophy type I, spinal muscular atrophy type II, congenital myopathy and congenital myotonic dystrophy were estimated to be 21.5 x 10-5, 4.1 x 10-5, 1.0 x 10-5, 5.8 x 10-5 and 5.2 x 10-5 respectively. The incidence of mitochondrial encephalomyopathies in preschool children (< 6 years of age) was 8.9 x 10-5, while the point prevalence in children < 16 years of age was 4.7 x 10-5. The median survival among cases with infantile onset was up to 12 years of age. The most common disorders were Leigh syndrome, Alpers syndrome and infantile mitochondrial myopathy with cytochrome C-oxidase deficiency. The investigated congenital myopathy showed autosomal dominant heredity with full penetrance. Characteristic clinical features were congenital joint contractures which normalized during early childhood, external ophthalmoplegia and proximal muscle weakness. The course was frequently progressive in adulthood. The major histopathologic changes in skeletal muscle in childhood were focal disorganization of myofilaments and type 2A-fiber hypoplasia. In adults with progressive muscle weakness, the muscle biopsies showed rimmed vacuoles with inclusions of 15-21 nm filaments. Linkage analysis, haplotype/recombination analysis and radiation hybrid mapping showed that the locus is located in 17p13 and that a myosin heavy-chain (MyHC) gene cluster colocalizes to the same region. DNA sequencing and mutation screening of the MyHC IIa gene identified a missense mutation, Glu706Lys, in a highly conserved region of the motor domain. Conclusions: Neuromuscular disorders appear to be more common in childhood than has been reported in previous studies. Our findings in a population-based study indicate that mitochondrial encephalomyopathies are relatively common neurometabolic disorders in childhood. There was a predominance of infantile and encephalopathic disorders with high mortality. A new congenital myopathy, which may be regarded as a variant of hereditary inclusion-body myopathy (h-IBM) was characterized. This is the first identification of a genetic defect in an h-IBM and also the first human myopathy associated with a mutation in a fast MyHC gene.
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| 29. |
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| 30. |
- Darin, Niklas, 1964, et al.
(författare)
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γ-glutamyl transpeptidase deficiency caused by a large homozygous intragenic deletion in GGT1.
- 2018
-
Ingår i: European journal of human genetics : EJHG. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 26, s. 808-817
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Tidskriftsartikel (refereegranskat)abstract
- γ-Glutamyl transpeptidase deficiency (glutathionuria, OMIM 231950) is a rare disease, with only six patients reported in the literature, although this condition has probably been underdiagnosed due the difficulty to routinely analyze glutathione in clinical samples and to the fact that no genetic defect has been coupled to the disease so far. We report two siblings with mild psychomotor developmental delay and mild neurological symptoms, who presented a markedly increased excretion of glutathione in urine and a very low γ-glutamyl transpeptidase activity in serum. Whole-genome sequencing revealed the presence of a 16.9kb homozygous deletion in GGT1, one of the genes encoding enzymes with γ-glutamyl transpeptidase activity in the human genome. Close analysis revealed the presence of a 13bp insertion at the deletion junction. This is the first report of a genetic variant as the cause of glutathionuria. In addition, genetic characterization of the patients' parents and a healthy sibling has provided direct genetic evidence regarding the autosomal recessive nature of this disease.
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| 31. |
- Donkervoort, S., et al.
(författare)
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Pathogenic Variants in the Myosin Chaperone UNC-45B Cause Progressive Myopathy with Eccentric Cores
- 2020
-
Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297. ; 107:6, s. 1078-1095
-
Tidskriftsartikel (refereegranskat)abstract
- The myosin-directed chaperone UNC-45B is essential for sarcomeric organization and muscle function from Caenorhabditis elegans to humans. The pathological impact of UNC-45B in muscle disease remained elusive. We report ten individuals with bi-allelic variants in UNC45B who exhibit childhood-onset progressive muscle weakness. We identified a common UNC45B variant that acts as a complex hypomorph splice variant. Purified UNC-45B mutants showed changes in folding and solubility. In situ localization studies further demonstrated reduced expression of mutant UNC-45B in muscle combined with abnormal localization away from the A-band towards the Z-disk of the sarcomere. The physiological relevance of these observations was investigated in C. elegans by transgenic expression of conserved UNC-45 missense variants, which showed impaired myosin binding for one and defective muscle function for three. Together, our results demonstrate that UNC-45B impairment manifests as a chaperonopathy with progressive muscle pathology, which discovers the previously unknown conserved role of UNC-45B in myofibrillar organization.
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| 32. |
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| 33. |
- Eggens, Veerle Rc, et al.
(författare)
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EXOSC3 mutations in pontocerebellar hypoplasia type 1: novel mutations and genotype-phenotype correlations.
- 2014
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Ingår i: Orphanet journal of rare diseases. - : Springer Science and Business Media LLC. - 1750-1172. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- Pontocerebellar hypoplasia (PCH) represents a group of neurodegenerative disorders with prenatal onset. Eight subtypes have been described thus far (PCH1-8) based on clinical and genetic features. Common characteristics include hypoplasia and atrophy of the cerebellum, variable pontine atrophy, and severe mental and motor impairments. PCH1 is distinctly characterized by the combination with degeneration of spinal motor neurons. Recently, mutations in the exosome component 3 gene (EXOSC3) have been identified in approximately half of the patients with PCH subtype 1.
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| 34. |
- Geoerger, B., et al.
(författare)
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Enasidenib treatment in two individuals with D-2-hydroxyglutaric aciduria carrying a germline IDH2 mutation
- 2023
-
Ingår i: Nature Medicine. - 1078-8956. ; 29:6
-
Tidskriftsartikel (refereegranskat)abstract
- D-2-hydroxyglutaric aciduria type II (D2HGA2) is a severe inborn disorder of metabolism caused by heterozygous R140 mutations in the IDH2 (isocitrate dehydrogenase 2) gene. Here we report the results of treatment of two children with D2HGA2, one of whom exhibited severe dilated cardiomyopathy, with the selective mutant IDH2 enzyme inhibitor enasidenib. In both children, enasidenib treatment led to normalization of D-2-hydroxyglutarate (D-2-HG) concentrations in body fluids. At doses of 50 mg and 60 mg per day, no side effects were observed, except for asymptomatic hyperbilirubinemia. For the child with cardiomyopathy, chronic D-2-HG inhibition was associated with improved cardiac function, and for both children, therapy was associated with improved daily functioning, global motility and social interactions. Treatment of the child with cardiomyopathy led to therapy-coordinated changes in serum phospholipid levels, which were partly recapitulated in cultured fibroblasts, associated with complex effects on lipid and redox-related gene pathways. These findings indicate that targeted inhibition of a mutant enzyme can partly reverse the pathology of a chronic neurometabolic genetic disorder. In a study of two children with the metabolic condition D-2-hydroxyglutaric aciduria type II, the drug enasidenib, developed as a selective mutant IDH2 inhibitor for treatment of acute myeloid leukemia, had beneficial effects on cardiac and neurodevelopmental abnormalities, indicating the potential for the repurposing of this drug for this hereditary condition.
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| 35. |
- Goemans, Nathalie M, et al.
(författare)
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Systemic administration of PRO051 in Duchenne's muscular dystrophy.
- 2011
-
Ingår i: The New England journal of medicine. - 1533-4406. ; 364:16, s. 1513-22
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Local intramuscular administration of the antisense oligonucleotide PRO051 in patients with Duchenne's muscular dystrophy with relevant mutations was previously reported to induce the skipping of exon 51 during pre-messenger RNA splicing of the dystrophin gene and to facilitate new dystrophin expression in muscle-fiber membranes. The present phase 1-2a study aimed to assess the safety, pharmacokinetics, and molecular and clinical effects of systemically administered PRO051.
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| 36. |
- Grønborg, Sabine, et al.
(författare)
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Leukoencephalopathy due to Complex II Deficiency and Bi-Allelic SDHB Mutations: Further Cases and Implications for Genetic Counselling.
- 2016
-
Ingår i: JIMD reports. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 2192-8304. ; 33, s. 69-77
-
Tidskriftsartikel (refereegranskat)abstract
- Isolated complex II deficiency is a rare cause of mitochondrial disease and bi-allelic mutations in SDHB have been identified in only a few patients with complex II deficiency and a progressive neurological phenotype with onset in infancy. On the other hand, heterozygous SDHB mutations are a well-known cause of familial paraganglioma/pheochromocytoma and renal cell cancer. Here, we describe two additional patients with respiratory chain deficiency due to bi-allelic SDHB mutations. The patients' clinical, neuroradiological, and biochemical phenotype is discussed according to current knowledge on complex II and SDHB deficiency and is well in line with previously described cases, thus confirming the specific neuroradiological presentation of complex II deficiency that recently has emerged. The patients' genotype revealed one novel SDHB mutation, and one SDHB mutation, which previously has been described in heterozygous form in patients with familial paraganglioma/pheochromocytoma and/or renal cell cancer. This is only the second example in the literature where one specific SDHx mutation is associated with both recessive mitochondrial disease in one patient and familial paraganglioma/pheochromocytoma in others. Due to uncertainties regarding penetrance of different heterozygous SDHB mutations, we argue that all heterozygous SDHB mutation carriers identified in relation to SDHB-related leukoencephalopathy should be referred to relevant surveillance programs for paraganglioma/pheochromocytoma and renal cell cancer. The diagnosis of complex II deficiency due to SDHB mutations therefore raises implications for genetic counselling that go beyond the recurrence risk in the family according to an autosomal recessive inheritance.
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| 37. |
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| 38. |
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| 39. |
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| 40. |
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| 41. |
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| 42. |
- Haas, Richard H, et al.
(författare)
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Mitochondrial disease: a practical approach for primary care physicians.
- 2007
-
Ingår i: Pediatrics. - : American Academy of Pediatrics (AAP). - 1098-4275 .- 0031-4005. ; 120:6, s. 1326-33
-
Tidskriftsartikel (refereegranskat)abstract
- Notorious variability in the presentation of mitochondrial disease in the infant and young child complicates its clinical diagnosis. Mitochondrial disease is not a single entity but, rather, a heterogeneous group of disorders characterized by impaired energy production due to genetically based oxidative phosphorylation dysfunction. Together, these disorders constitute the most common neurometabolic disease of childhood with an estimated minimal risk of developing mitochondrial disease of 1 in 5000. Diagnostic difficulty results from not only the variable and often nonspecific presentation of these disorders but also from the absence of a reliable biomarker specific for the screening or diagnosis of mitochondrial disease. A simplified and standardized approach to facilitate the clinical recognition of mitochondrial disease by primary physicians is needed. With this article we aimed to improve the clinical recognition of mitochondrial disease by primary care providers and empower the generalist to initiate appropriate baseline diagnostic testing before determining the need for specialist referral. This is particularly important in light of the international shortage of metabolism specialists to comprehensively evaluate this large and complex disease population. It is hoped that greater familiarity among primary care physicians with the protean manifestations of mitochondrial disease will facilitate the proper diagnosis and management of this growing cohort of pediatric patients who present across all specialties.
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| 43. |
- Heard, J. M., et al.
(författare)
-
Availability, accessibility and delivery to patients of the 28 orphan medicines approved by the European Medicine Agency for hereditary metabolic diseases in the MetabERN network
- 2020
-
Ingår i: Orphanet Journal of Rare Diseases. - : Springer Science and Business Media LLC. - 1750-1172. ; 15:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background The European Medicine Agency granted marketing approval to 164 orphan medicinal products for rare diseases, among which 28 products intended for the treatment of hereditary metabolic diseases. Taking advantage of its privileged connection with 69 healthcare centres of excellence in this field, MetabERN, the European Reference Network for hereditary metabolic diseases, performed a survey asking health care providers from 18 European countries whether these products are available on the market, reimbursed and therefore accessible for prescription, and actually delivered in their centre. Results Responses received from 52 centres (75%) concerned the design of treatment plans, the access to marketed products, and the barriers to delivery. Treatment options are always discussed with patients, who are often involved in their treatment plan. Most products (26/28) are available in most countries (15/18). Among the 15 broadly accessible products (88.5% of the centres), 9 are delivered to most patients (mean 70.1%), and the others to only few (16.5%). Among the 10 less accessible products (40.2% of the centres), 6 are delivered to many patients (66.7%), and 4 are rarely used (6.3%). Information was missing for 3 products. Delay between prescription and delivery is on average one month. Beside the lack of availability or accessibility, the most frequent reasons for not prescribing a treatment are patients' clinical status, characteristic, and personal choice. Conclusions Data collected from health care providers in the MetabERN network indicate that two-third of the orphan medicines approved by EMA for the treatment of hereditary metabolic diseases are accessible to treating patients, although often less than one-half of the patients with the relevant conditions actually received the approved product to treat their disease. Thus, in spite of the remarkable achievement of many products, patients concerned by EMA-approved orphan medicinal products have persistent unmet needs, which deserve consideration. The enormous investments made by the companies to develop products, and the high financial burden for the Member States to purchase these products emphasize the importance of a scrupulous appreciation of treatment value involving all stakeholders at early stage of development, before marketing authorization, and during follow up.
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| 44. |
- Hedberg, Carola, 1969, et al.
(författare)
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B3GALNT2 is a gene associated with congenital muscular dystrophy with brain malformations.
- 2014
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 22:5, s. 707-710
-
Tidskriftsartikel (refereegranskat)abstract
- Congenital muscular dystrophies associated with brain malformations are a group of disorders frequently associated with aberrant glycosylation of α-dystroglycan. They include disease entities such a Walker-Warburg syndrome, muscle-eye-brain disease and various other clinical phenotypes. Different genes involved in glycosylation of α-dystroglycan are associated with these dystroglycanopathies. We describe a 5-year-old girl with psychomotor retardation, ataxia, spasticity, muscle weakness and increased serum creatine kinase levels. Immunhistochemistry of skeletal muscle revealed reduced glycosylated α-dystroglycan. Magnetic resonance imaging of the brain at 3.5 years of age showed increased T2 signal from supratentorial and infratentorial white matter, a hypoplastic pons and subcortical cerebellar cysts. By whole exome sequencing, the patient was identified to be compound heterozygous for a one-base duplication and a missense mutation in the gene B3GALNT2 (β-1,3-N-acetylgalactosaminyltransferase 2; B3GalNAc-T2). This patient showed a milder phenotype than previously described patients with mutations in the B3GALNT2 gene.European Journal of Human Genetics advance online publication, 2 October 2013; doi:10.1038/ejhg.2013.223.
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| 45. |
- Hikmat, Omar, et al.
(författare)
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Elevated cerebrospinal fluid protein in POLG-related epilepsy: Diagnostic and prognostic implications.
- 2018
-
Ingår i: Epilepsia. - : Wiley. - 1528-1167 .- 0013-9580. ; 59:8, s. 1595-1602
-
Tidskriftsartikel (refereegranskat)abstract
- Epilepsy is common in individuals with mutations in POLG, the gene encoding the catalytic subunit of the mitochondrial DNA polymerase gamma. Early recognition and aggressive seizure management are crucial for patient survival. Disruption of the blood-brain barrier (BBB) is implicated in various neurological disorders including epilepsy. The aim of this study was to assess whether POLG-related disease is associated with BBB dysfunction and what clinical implications this has for patients.Our retrospective study used data from 83 patients with pathogenic POLG mutations from 4 countries--Norway, Sweden, Finland, and the United Kingdom. Data were collected using a structured questionnaire. We used the presence of raised cerebrospinal fluid (CSF) protein and a raised CSF/serum ratio of albumin (Q-alb) to evaluate the integrity of the blood-CSF barrier.Raised CSF protein was found in 70% of patients (n = 58/83) and appeared to be associated with the most severe phenotypes. In those in whom it was measured, the Q-alb ratio was markedly elevated (n = 18). The majority of those with epilepsy (n = 50/66, 76%) had raised CSF protein, and this preceded seizure debut in 75% (n = 15/20). The median survival time from symptom onset for those with raised CSF protein was decreased (13 months) compared to those with normal CSF protein (32 months).Our results indicate that there is disruption of the BBB in POLG-related disease, as evidenced by a raised CSF protein and Q-alb ratio. We also find that raised CSF protein is a common finding in patients with POLG disease. Our data suggest that the presence of BBB dysfunction predicts a poorer outcome, and elevated CSF protein may therefore be an additional biomarker both for early diagnosis and to identify those at high risk of developing epilepsy.
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| 46. |
- Hikmat, O., et al.
(författare)
-
Expanding the phenotypic spectrum of BCS1L-related mitochondrial disease
- 2021
-
Ingår i: Annals of Clinical and Translational Neurology. - : Wiley. - 2328-9503. ; 8:11, s. 2155-2165
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To delineate the full phenotypic spectrum of BCS1L-related disease, provide better understanding of the genotype-phenotype correlations and identify reliable prognostic disease markers. Methods: We performed a retrospective multinational cohort study of previously unpublished patients followed in 15 centres from 10 countries. Patients with confirmed biallelic pathogenic BCS1L variants were considered eligible. Clinical, laboratory, neuroimaging and genetic data were analysed. Patients were stratified into different groups based on the age of disease onset, whether homozygous or compound heterozygous for the c.232A>G (p.Ser78Gly) variant, and those with other pathogenic BCS1L variants. Results: Thirty-three patients were included. We found that growth failure, lactic acidosis, tubulopathy, hepatopathy and early death were more frequent in those with disease onset within the first month of life. In those with onset after 1 month, neurological features including movement disorders and seizures were more frequent. Novel phenotypes, particularly involving movement disorder, were identified in this group. The presence of the c.232A>G (p.Ser78Gly) variant was associated with significantly worse survival and exclusively found in those with disease onset within the first month of life, whilst other pathogenic BCS1L variants were more frequent in those with later symptom onset. Interpretation: The phenotypic spectrum of BCS1L-related disease comprises a continuum of clinical features rather than a set of separate syndromic clinical identities. Age of onset defines BCS1L-related disease clinically and early presentation is associated with poor prognosis. Genotype correlates with phenotype in the presence of the c.232A>G (p.Ser78Gly) variant.
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| 47. |
- Hikmat, O., et al.
(författare)
-
Simplifying the clinical classification of polymerase gamma (POLG) disease based on age of onset; studies using a cohort of 155 cases
- 2020
-
Ingår i: Journal of Inherited Metabolic Disease. - : Wiley. - 0141-8955 .- 1573-2665. ; 43:4, s. 726-736
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Variants in POLG are one of the most common causes of inherited mitochondrial disease. Phenotypic classification of POLG disease has evolved haphazardly making it complicated and difficult to implement in everyday clinical practise. The aim of our study was to simplify the classification and facilitate better clinical recognition. Methods: A multinational, retrospective study using data from 155 patients with POLG variants recruited from seven European countries. Results: We describe the spectrum of clinical features associated with POLG variants in the largest known cohort of patients. While clinical features clearly form a continuum, stratifying patients simply according to age of onset—onset prior to age 12 years; onset between 12 and 40 years and onset after the age of 40 years, permitted us to identify clear phenotypic and prognostic differences. Prior to 12 years of age, liver involvement (87%), seizures (84%), and feeding difficulties (84%) were the major features. For those with onset between 12 and 40 years, ataxia (90%), peripheral neuropathy (84%), and seizures (71%) predominated, while for those with onset over 40 years, ptosis (95%), progressive external ophthalmoplegia (89%), and ataxia (58%) were the major clinical features. The earlier the onset the worse the prognosis. Patients with epilepsy and those with compound heterozygous variants carried significantly worse prognosis. Conclusion: Based on our data, we propose a simplified POLG disease classification, which can be used to guide diagnostic investigations and predict disease course. © 2020 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM
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| 48. |
- Hikmat, Omar, et al.
(författare)
-
Status epilepticus in POLG disease: a large multinational study
- 2024
-
Ingår i: JOURNAL OF NEUROLOGY. - 0340-5354 .- 1432-1459.
-
Tidskriftsartikel (refereegranskat)abstract
- We aimed to provide a detailed phenotypic description of status epilepticus (SE) in a large cohort of patients with POLG disease and identify prognostic biomarkers to improve the management of this life-threatening condition. In a multinational, retrospective study with data on patients with POLG disease from seven European countries, we identified those who had SE. The age of SE onset, accompanying clinical, laboratory, imaging and genetic findings were analysed. One hundred and ninety-five patients with genetically confirmed POLG disease were recruited, of whom 67% (130/194) had epilepsy. SE was identified in 77% (97/126), with a median age of SE onset of 7 years. SE was the presenting symptom of the disease in 43% (40/93) of those with SE, while 57% (53/93) developed SE during the disease course. Convulsive SE was reported in 97% (91/94) followed by epilepsia partialis continua in 67% (56/84). Liver impairment 78% (74/95), ataxia 69% (60/87), stroke-like episodes 57% (50/88), were the major comorbidities. In the majority (66%; 57/86) with SE this became refractory or super-refractory. The presence of seizures was associated with significantly higher mortality compared to those without (P <= 0.001). The median time from SE debut to death was 5 months. SE is a major clinical feature of POLG disease in early and juvenile to adult-onset disease and can be the presenting feature or arise as part of a multisystem disease. It is associated with high morbidity and mortality, with the majority of patients with SE going on to develop refractory or super-refractory SE.
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| 49. |
- Hikmat, O., et al.
(författare)
-
The impact of gender, puberty, and pregnancy in patients with POLG disease
- 2020
-
Ingår i: Annals of Clinical and Translational Neurology. - : Wiley. - 2328-9503. ; 7:10, s. 2019-2025
-
Tidskriftsartikel (refereegranskat)abstract
- Objective To study the impact of gender, puberty, and pregnancy on the expression of POLG disease, one of the most common mitochondrial diseases known. Methods Clinical, laboratory, and genetic data were collected retrospectively from 155 patients with genetically confirmed POLG disease recruited from seven European countries. We used the available data to study the impact of gender, puberty, and pregnancy on disease onset and deterioration. Results We found that disease onset early in life was common in both sexes but there was also a second peak in females around the time of puberty. Further, pregnancy had a negative impact with 10 of 14 women (71%) experiencing disease onset or deterioration during pregnancy. Interpretation Gender clearly influences the expression of POLG disease. While onset very early in life was common in both males and females, puberty in females appeared associated both with disease onset and increased disease activity. Further, both disease onset and deterioration, including seizure aggravation and status epilepticus, appeared to be associated with pregnancy. Thus, whereas disease activity appears maximal early in life with no subsequent peaks in males, both menarche and pregnancy appear associated with disease onset or worsening in females. This suggests that hormonal changes may be a modulating factor.
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| 50. |
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