| 1. |
- Hedberg, Carola, 1969, et al.
(författare)
-
Autosomal dominant myofibrillar myopathy with arrhythmogenic right ventricular cardiomyopathy 7 is caused by a DES mutation
- 2012
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 20:9, s. 984-985
-
Tidskriftsartikel (refereegranskat)abstract
- Using exome sequencing we searched for the genetic cause of autosomal dominant myofibrillar myopathy with arrhythmogenic right ventricular cardiomyopathy (ARVC) in a Swedish family. A heterozygous C-to-T transition, c.1255C>T, p.Pro419Ser in the desmin gene on chromosome 2q35, was identified. Previous studies had demonstrated linkage to chromosome 10q22.3, but no causative mutation had been found in that region. Sanger sequencing of DNA from 17 family members confirmed the heterozygous c.1255C>T desmin mutation in seven out of ten family members that had been classified as affected in the previous study. Our new results demonstrate the usefulness of next-generation sequencing, and the diagnostic difficulties with some forms of dominantly inherited muscle diseases as they can display a wide clinical and morphological variability even within a given family. European Journal of Human Genetics (2012) 20, 984-985; doi:10.1038/ejhg.2012.39; published online 7 March 2012
|
|
| 2. |
- Hedberg, Carola, 1969, et al.
(författare)
-
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.
|
|
| 3. |
- Hedberg, Carola, 1969, et al.
(författare)
-
Reply to Brodehl et al.
- 2013
-
Ingår i: European journal of human genetics : EJHG. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 21:6
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 4. |
- Kollberg, Gittan, 1963, et al.
(författare)
-
Low frequency of mtDNA point mutations in patients with PEO associated with POLG1 mutations.
- 2005
-
Ingår i: European journal of human genetics : EJHG. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 13:4, s. 463-9
-
Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial myopathy in progressive external ophthalmoplegia (PEO) has been associated with POLG1 mutations. POLG1 encodes the catalytic alpha subunit of polymerase gamma and is the only polymerase known to be involved in mtDNA replication. It has two functionally different domains, one polymerase domain and one exonuclease domain with proofreading activity. In this study we have investigated whether mtDNA point mutations are involved, directly or indirectly, in the pathogenesis of PEO. Muscle biopsy specimens from patients with POLG1 mutations, affecting either the exonuclease or the polymerase domain, were investigated. Single cytochrome c oxidase (COX)-deficient muscle fibers were dissected and screened for clonally expanded mtDNA point mutations using a sensitive denaturing gradient gel electrophoresis analysis, in which three different regions of mtDNA, including five different tRNA genes, were investigated. To screen for randomly distributed mtDNA point mutations in muscle, two regions of mtDNA including deletion breakpoints were investigated by high-fidelity PCR, followed by cloning and sequencing. Long-range PCR revealed multiple mtDNA deletions in all the patients but not the controls. No point mutations were identified in single COX-deficient muscle fibers. Cloning and sequencing of muscle homogenate identified randomly distributed point mutations at very low frequency in patients and controls (<1:50 000). We conclude that mtDNA point mutations do not appear to be directly or indirectly involved in the pathogenesis of mitochondrial disease in patients with different POLG1 mutations.
|
|
| 5. |
- Oldfors Hedberg, Carola, 1969, et al.
(författare)
-
A new early-onset neuromuscular disorder associated with kyphoscoliosis peptidase (KY) deficiency.
- 2016
-
Ingår i: European journal of human genetics : EJHG. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 24:12, s. 1771-1777
-
Tidskriftsartikel (refereegranskat)abstract
- We describe a new early-onset neuromuscular disorder due to a homozygous loss-of-function variant in the kyphoscoliosis peptidase gene (KY). A 7.5-year-old girl with walking difficulties from 2 years of age presented with generalized muscle weakness; mild contractures in the shoulders, hips and feet; cavus feet; and lordosis but no scoliosis. She had previously been operated with Achilles tendon elongation. Whole-body MRI showed atrophy and fatty infiltration in the calf muscles. Biopsy of the vastus lateralis muscle showed variability in fiber size, with some internalized nuclei and numerous very small fibers with variable expression of developmental myosin heavy chain isoforms. Some small fibers showed abnormal sarcomeres with thickened Z-discs and small nemaline rods. Whole-exome sequencing revealed a homozygous one-base deletion (c.1071delG, p.(Thr358Leufs*3)) in KY, predicted to result in a truncated protein. Analysis of an RNA panel showed that KY is predominantly expressed in skeletal muscle in humans. A recessive variant in the murine ortholog Ky was previously described in a spontaneously generated mouse mutant with kyphoscoliosis, which developed postnatally and was caused by dystrophy of postural muscles. The abnormal distribution of Xin and Ky-binding partner filamin C in the muscle fibers of our patient was highly similar to their altered localization in ky/ky mouse muscle fibers. We describe the first human case of disease associated with KY inactivation. As in the mouse model, the affected child showed a neuromuscular disorder - but in contrast, no kyphoscoliosis.
|
|
| 6. |
- Oldfors Hedberg, Carola, 1969, et al.
(författare)
-
Ribonuclease inhibitor 1 (RNH1) deficiency cause congenital cataracts and global developmental delay with infection-induced psychomotor regression and anemia
- 2023
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438.
-
Tidskriftsartikel (refereegranskat)abstract
- Ribonuclease inhibitor 1, also known as angiogenin inhibitor 1, encoded by RNH1, is a ubiquitously expressed leucine-rich repeat protein, which is highly conserved in mammalian species. Inactivation of rnh1 in mice causes an embryonically lethal anemia, but the exact biological function of RNH1 in humans remains unknown and no human genetic disease has so far been associated with RNH1. Here, we describe a family with two out of seven siblings affected by a disease characterized by congenital cataract, global developmental delay, myopathy and psychomotor deterioration, seizures and periodic anemia associated with upper respiratory tract infections. A homozygous splice-site variant (c.615-2A > C) in RNH1 segregated with the disease. Sequencing of RNA derived from patient fibroblasts and cDNA analysis of skeletal muscle mRNA showed aberrant splicing with skipping of exon 7. Western blot analysis revealed a total lack of the RNH1 protein. Functional analysis revealed that patient fibroblasts were more sensitive to RNase A exposure, and this phenotype was reversed by transduction with a lentivirus expressing RNH1 to complement patient cells. Our results demonstrate that loss-of-function of RNH1 in humans is associated with a multiorgan developmental disease with recessive inheritance. It may be speculated that the infection-induced deterioration resulted from an increased susceptibility toward extracellular RNases and/or other inflammatory responses normally kept in place by the RNase inhibitor RNH1.
|
|
| 7. |
- Roos, Sara, 1979, et al.
(författare)
-
A novel mitochondrial tRNA Arg mutation resulting in an anticodon swap in a patient with mitochondrial encephalomyopathy.
- 2013
-
Ingår i: European journal of human genetics : EJHG. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 21:5, s. 571-3
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We report a mutation in the anticodon of the tRNA(Arg) gene (m.10437G>A), resulting in an anticodon swap from GCU to ACU, which is the anticodon of tRNA(Trp), in a boy with mitochondrial encephalomyopathy. Enzyme histochemical analysis of muscle tissue and biochemical analysis of isolated muscle mitochondria demonstrated cytochrome c oxidase (COX) deficiency. Restriction fragment length polymorphism analysis showed that 90% of muscle and 82% of urinary epithelium mtDNA harbored the mutation. The mutation was not identified in blood, fibroblasts, hair roots, or buccal epithelial cells and it was absent in the asymptomatic mother, suggesting that it was a de novo mutation. Single-fiber PCR analysis showed that the proportion of mutated mtDNA correlated with enzyme histochemical COX deficiency. This mutation adds to the three previously described disease-causing mutations in tRNA(Arg), but it is the first mutation occurring in the anticodon of tRNA(Arg).European Journal of Human Genetics advance online publication, 11 July 2012; doi:10.1038/ejhg.2012.153.
|
|
| 8. |
- Roos, Sara, 1979, et al.
(författare)
-
Mitochondrial complex IV deficiency caused by a novel frameshift variant in MT-CO2 associated with myopathy and perturbed acylcarnitine profile
- 2019
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 27:2, s. 331-335
-
Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial myopathies are a heterogeneous group of disorders associated with a wide range of clinical phenotypes. We present a 16-year-old girl with a history of exercise intolerance since childhood. Acylcarnitine species suggestive of multiple acyl-CoA dehydrogenase deficiency were found in serum, however genetic analysis did not reveal variants in genes associated with this disorder. Biochemical analyses of skeletal muscle mitochondria revealed an isolated and extremely low activity of cytochrome c oxidase (COX). This finding was confirmed by enzyme histochemistry, which demonstrated an almost complete absence of fibers with normal COX activity. Whole-exome sequencing revealed a single base-pair deletion (m.8088delT) in MT-CO2, which encodes subunit 2 of COX, resulting in a premature stop codon. Restriction fragment length polymorphism-analysis confirmed mtDNA heteroplasmy with high mutant load in skeletal muscle, the only clinically affected tissue, but low levels in other investigated tissues. Single muscle fiber analysis showed segregation of the mutant genotype with respiratory chain dysfunction. Immuno-histochemical studies indicated that the truncating variant in COX2 has an inhibitory effect on the assembly of the COX holoenzyme.
|
|
| 9. |
- Tajsharghi, Homa, et al.
(författare)
-
Mutations and sequence variation in the human myosin heavy chain IIa gene (MYH2)
- 2005
-
Ingår i: European Journal of Human Genetics. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 13:5, s. 617-22
-
Tidskriftsartikel (refereegranskat)abstract
- We recently described a new autosomal dominant myopathy associated with a missense mutation in the myosin heavy chain (MyHC) IIa gene (MYH2). In this study, we performed mutation analysis of MYH2 in eight Swedish patients with familial myopathy of unknown cause. In two of the eight index cases, we identified novel heterozygous missense mutations in MYH2, one in each case: V970I and L1061V. The mutations were located in subfragment 2 of the MyHC and they changed highly conserved residues. Most family members carrying the mutations had signs and symptoms consisting mainly of mild muscle weakness and myalgia. In addition, we analyzed the extent and distribution of nucleotide variation in MYH2 in 50 blood donors, who served as controls, by the complete sequencing of all 38 exons comprising the coding region. We identified only six polymorphic sites, five of which were synonymous polymorphisms. One variant, which occurred at an allele frequency of 0.01, was identical to the L1061V that was also found in one of the families with myopathy. The results of the analysis of normal variation indicate that there is strong selective pressure against mutations in MYH2. On the basis of these results, we suggest that MyHC genes should be regarded as candidate genes in cases of hereditary myopathies of unknown etiology.
|
|
| 10. |
- Tajsharghi, Homa, et al.
(författare)
-
Recessive myosin myopathy with external ophthalmoplegia associated with MYH2 mutations
- 2014
-
Ingår i: European Journal of Human Genetics. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 22:6, s. 801-808
-
Tidskriftsartikel (refereegranskat)abstract
- Myosin myopathies comprise a group of inherited diseases caused by mutations in myosin heavy chain (MyHC) genes. Homozygous or compound heterozygous truncating MYH2 mutations have been demonstrated to cause recessive myopathy with ophthalmoplegia, mild-to-moderate muscle weakness and complete lack of type 2A muscle fibers. In this study, we describe for the first time the clinical and morphological characteristics of recessive myosin IIa myopathy associated with MYH2 missense mutations. Seven patients of five different families with a myopathy characterized by ophthalmoplegia and mild-to-moderate muscle weakness were investigated. Muscle biopsy was performed to study morphological changes and MyHC isoform expression. Five of the patients were homozygous for MYH2 missense mutations, one patient was compound heterozygous for a missense and a nonsense mutation and one patient was homozygous for a frame-shift MYH2 mutation. Muscle biopsy demonstrated small or absent type 2A muscle fibers and reduced or absent expression of the corresponding MyHC IIa transcript and protein. We conclude that mild muscle weakness and ophthalmoplegia in combination with muscle biopsy demonstrating small or absent type 2A muscle fibers are the hallmark of recessive myopathy associated with MYH2 mutations.
|
|
