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| 2. |
- Arzoo, Pakeeza Shaiq, et al.
(författare)
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WNT10A Mutations Account for 1/4 of Population- Based Isolated Oligodontia and Show Phenotypic Correlations
- 2014
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Ingår i: American Journal of Medical Genetics. Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 164:2, s. 353-359
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Tidskriftsartikel (refereegranskat)abstract
- A large proportion (>50%) of patients with isolated oligodontia were recently reported with WNT10A mutations. We have analyzed a population-based cohort of 102 individuals diagnosed with non-syndromic oligodontia and a mean of 8.2 missing teeth. The cohort included 94 families and screening of WNT10A identified that 26 probands (27.7%) had at least one WNT10A variant. When we included the MSX1, PAX9, AXIN2, EDA, EDAR, and EDARADD genes, 38.3% of probands were positive for a mutation. Biallelic WNT10A mutations were strongly associated with a larger number of missing teeth (11.09) when compared to both monoallelic WNT10 mutations (6.82) and the group without mutations in WNT10A, MSX1, PAX9, AXIN2, EDA, EDAR, or EDARADD (7.77). Genotype-phenotype analysis of individuals with WNT10A mutations showed that premolars were the most common missing teeth. Furthermore, biallelic WNT10A mutations were associated with absence of maxillary and mandibular molars as well as mandibular central incisors. Maxillary central incisors were always present. Thus, our study indicates that WNT10A mutations are associated with both the type and numbers of missing teeth. Furthermore, we show that this population-based cohort of isolated oligodontia had a considerably lower frequency of mutated WNT10A alleles and a lower mean number of missing teeth when compared to patients recruited from dental specialist centers. (c) 2013 Wiley Periodicals, Inc.
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| 3. |
- Bergendal, Birgitta, et al.
(författare)
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Isolated Oligodontia Associated With Mutations in EDARADD, AXIN2, MSX1, and PAX9 Genes
- 2011
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Ingår i: American Journal of Medical Genetics Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 155:7, s. 1616-1622
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Tidskriftsartikel (refereegranskat)abstract
- Oligodontia is defined as the congenital lack of six or more permanent teeth, excluding third molars. Oligodontia as well as hypodontia (lack of one or more permanent teeth) are highly heritable conditions associated with mutations in the AXIN2, MSX1, PAX9, EDA, and EDAR genes. Here we define the prevalence of mutations in the AXIN2, MSX1, PAX9, EDA, and EDAR genes, and the novel candidate gene EDARADD in a cohort of 93 Swedish probands with non-syndromic, isolated oligodontia. Mutation screening was performed using denaturing gradient gel electrophoresis and DNA sequence analysis. Analyses of the coding sequences of the six genes showed sequence alterations predicted to be damaging or potentially damaging in ten of 93 probands (10.8%). Mutations were identified in the EDARADD (n = 1), AXIN2 (n = 3), MSX1 (n = 2), and PAX9 (n = 4) genes, respectively. None of the 10 probands with mutations had other self-reported symptoms from ectodermal tissues. The oral parameters were similar when comparing individuals with and without mutations but a family history of oligodontia was three times more frequent for probands with mutations. EDARADD mutations have previously been reported in a few families segregating hypohidrotic ectodermal dysplasia and this is, to our knowledge, the first report of an EDARADD mutation associated with isolated oligodontia.
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- Björk, Aron H., et al.
(författare)
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Antibody deficiency in adults with 22q11.2 deletion syndrome.
- 2012
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Ingår i: American journal of medical genetics. Part A. - : Wiley. - 1552-4833 .- 1552-4825. ; 158A:8, s. 1934-1940
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Tidskriftsartikel (refereegranskat)abstract
- There are limited data on immunological disorders, infection profile, and autoimmunity among adults with the 22q11.2 deletion syndrome (22q11.2DS) in the literature. To expand this knowledge base, we evaluated immunoglobulin levels, lymphocyte subsets, and T-cell function in 26 adults, consecutively referred to our 22q11.2DS multidisciplinary team. Their medical records were also reviewed with respect to frequency and severity of infections and autoimmune disorders. Six patients had low immunoglobulin levels; among these patients, one had a combined IgA and IgG1 deficiency, one had an isolated IgG3 deficiency, and four had a profound antibody deficiency comparable to common variable immunodeficiency (CVID). Three of the patients with profound antibody deficiency showed signs of reduced T-cell function measured as a low response to mitogen and/or antigen stimulation. The four patients with profound antibody deficiency suffered from more severe infections than the rest of the patient group. Three of them also had a history of both immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AHA). Our results suggest that a subgroup of individuals with 22q11.2DS can develop a severe antibody deficiency associated with lower respiratory tract infections and autoimmune conditions. Early diagnosis of hypogammaglobulinemia among these individuals is important in order to provide optimal treatment. We therefore recommend an immunological evaluation and follow-up among adults with 22q11.2DS who have a history of autoimmune conditions or recurrent infections. © 2012 Wiley Periodicals, Inc.
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| 7. |
- Ekvall, Sara, et al.
(författare)
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Co-Occurring SHOC2 and PTPN11 Mutations in a Patient With Severe/Complex Noonan Syndrome-Like Phenotype
- 2011
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Ingår i: American Journal of Medical Genetics Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 155:6, s. 1217-1224
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Tidskriftsartikel (refereegranskat)abstract
- Noonan syndrome (NS) is a heterogeneous disorder caused by activating mutations in the RAS-MAPK signaling pathway. It is associated with variable clinical expression including short stature, congenital heart defect, unusual pectus deformity, and typical facial features and the inheritance is autosomal dominant. Here, we present a clinical and molecular characterization of a patient with Noonan-like syndrome with loose anagen hair phenotype and additional features including mild psychomotor developmental delay, osteoporosis, gingival hyperplasia, spinal neuroblastoma, intrathoracic extramedullary hematopoiesis, and liver hemangioma. Mutation analysis of PTPN11, SOS1, RAF1, KRAS, BRAF, MEK1, MEK2, NRAS, and SHOC2 was conducted, revealing a co-occurrence of two heterozygous previously identified mutations in the index patient. The mutation SHOC2 c.4A> G; p.Ser2Gly represents a de novo mutation, whereas, PTPN11 c. 1226G>C; p.Gly409Ala was inherited from the mother and also identified in the brother. The mother and the brother present with some NS manifestations, such as short stature, delayed puberty, keratosis pilaris, cafe-au-lait spots, refraction error (mother), and undescended testis (brother), but no NS facial features, supporting the notion that the PTPN11 p. Gly409Ala mutation leads to a relatively mild phenotype. We propose that, the atypical phenotype of the young woman with NS reported here is an additive effect, where the PTPN11 mutation acts as a modifier. Interestingly, co-occurrence of RAS-MAPK mutations has been previously identified in a few patients with variable NS or neurofibromatosis-NS phenotypes. Taken together, the results suggest that co-occurrence of mutations or modifying loci in the RAS-MAPK pathway may contribute to the clinical variability observed among NS patients.
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| 8. |
- Ekvall, Sara, 1982-, et al.
(författare)
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Novel association of neurofibromatosis type 1-causing mutations in families with neurofibromatosis-Noonan syndrome
- 2014
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Ingår i: American Journal of Medical Genetics. Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 164:3, s. 579-587
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Tidskriftsartikel (refereegranskat)abstract
- Neurofibromatosis-Noonan syndrome (NFNS) is a rare condition with clinical features of both neurofibromatosis type 1 (NF1) and Noonan syndrome (NS). All three syndromes belong to the RASopathies, which are caused by dysregulation of the RAS-MAPK pathway. The major gene involved in NFNS is NF1, but co-occurring NF1 and PTPN11 mutations in NFNS have been reported. Knowledge about possible involvement of additional RASopathy-associated genes in NFNS is, however, very limited. We present a comprehensive clinical and molecular analysis of eight affected individuals from three unrelated families displaying features of NF1 and NFNS. The genetic etiology of the clinical phenotypes was investigated by mutation analysis, including NF1, PTPN11, SOS1, KRAS, NRAS, BRAF, RAF1, SHOC2, SPRED1, MAP2K1, MAP2K2, and CBL. All three families harbored a heterozygous NF1 variant, where the first family had a missense variant, c.5425C>T;p.R1809C, the second family a recurrent 4bp-deletion, c.6789_6792delTTAC;p.Y2264Tfs*6, and the third family a splice-site variant, c.2991-1G>A, resulting in skipping of exon 18 and an in-frame deletion of 41 amino acids. These NF1 variants have all previously been reported in NF1 patients. Surprisingly, both c.6789_6792delTTAC and c.2991-1G>A are frequently associated with NF1, but association to NFNS has, to our knowledge, not previously been reported. Our results support the notion that NFNS represents a variant of NF1, genetically distinct from NS, and is caused by mutations in NF1, some of which also cause classical NF1. Due to phenotypic overlap between NFNS and NS, we propose screening for NF1 mutations in NS patients, preferentially when café-au-lait spots are present.
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| 9. |
- Englund, Annika, et al.
(författare)
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Changes in mortality and causes of death in the Swedish Down syndrome population
- 2013
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Ingår i: American Journal of Medical Genetics. Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 161A:4, s. 642-649
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Tidskriftsartikel (refereegranskat)abstract
- During the past few decades age at death for individuals with Down syndrome (DS) has increased dramatically. The birth frequency of infants with DS has long been constant in Sweden. Thus, the prevalence of DS in the population is increasing. The aim of the present study was to analyze mortality and causes of death in individuals with DS during the period 19692003. All individuals with DS that died between 1969 and 2003 in Sweden, and all individuals born with DS in Sweden between 1974 and 2003 were included. Data were obtained from the Swedish Medical Birth Register, the Swedish Birth Defects Register, and the National Cause of Death Register. Median age at death has increased by 1.8 years per year. The main cause of death was pneumonia. Death from congenital heart defects decreased. Death from atherosclerosis was rare but more frequent than reported previously. Dementia was not reported in any subjects with DS before 40 years of age, but was a main or contributing cause of death in 30% of the older subjects. Except for childhood leukemia, cancer as a cause of death was rare in all age groups. Mortality in DS, particularly infant mortality, has decreased markedly during the past decades. Median age at death is increasing and is now almost 60 years. Death from cancer is rare in DS, but death from dementia is common.
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| 10. |
- Glueckert, Rudolf, et al.
(författare)
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Histology and synchrotron radiation-based microtomography of the inner ear in a molecularly confirmed case of CHARGE syndrome
- 2010
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Ingår i: American journal of medical genetics. Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 152A:3, s. 665-673
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Tidskriftsartikel (refereegranskat)abstract
- CHARGE (Coloboma of the iris or retina, heart defects, atresia of the choanae, retardation of growth and/or development, genital anomalies, ear anomalies) syndrome (OMIM #214800) affects about 1 in 10,000 children and is most often caused by chromodomain helicase DNA-binding protein-7 (CHD7) mutations. Inner ear defects and vestibular abnormalities are particularly common. Specifically, semicircular canal (SCC) hypoplasia/aplasia and the presence of a Mondini malformation can be considered pathognomonic in the context of congenital malformations of the CHARGE syndrome. We obtained a temporal bone (TB) of a patient with CHARGE syndrome who died from bacteremia at 3 months of age. The clinical diagnosis was confirmed in the patient by direct DNA sequencing and the detection of a de novo, truncating CHD7 mutation, c.6169dup (p.R2057fs). We assessed changes of the TB and the degree of neural preservation, which may influence the potential benefit of cochlear implantation. The TB was analyzed using synchrotron radiation-based micro computed tomography, and by light microscopy. The vestibular partition consisted of a rudimentary vestibule with agenesis of the SCCs. The cochlea was hypoplastic with poor or deficient interscaling and shortened (Mondini dysplasia). The organ of Corti had near normal structure and innervation. Modiolus and Rosenthal's canal were hypoplastic with perikarya displaced along the axon bundles into the internal acoustic meatus, which may be explained by the arrest or limited migration and translocation of the cell nuclei into the cochlear tube during development.
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