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| 2. |
- Akram, Talia, et al.
(author)
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Aberrant splicing due to a novel RPS7 variant causes Diamond-Blackfan Anemia associated with spontaneous remission and meningocele
- 2020
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In: International Journal of Hematology. - : Springer Science and Business Media LLC. - 0925-5710 .- 1865-3774. ; 112:6, s. 894-899
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Journal article (peer-reviewed)abstract
- Diamond-Blackfan Anemia (DBA) is a congenital pure red cell aplasia caused by heterozygous variants in ribosomal protein genes. The hematological features associated with DBA are highly variable and non-hematological abnormalities are common. We report herein on an affected mother and her daughter presenting with transfusion-dependent anemia. The mother showed mild physical abnormalities and entered spontaneous remission at age 13 years. Her daughter was born with occipital meningocele. Exome sequencing of DNA from the mother revealed a heterozygous novel splice site variant (NM_001011.4:c.508-3T > G) in the Ribosomal Protein S7 gene (RPS7) inherited by the daughter. Functional analysis of the RPS7 variant expressed from a mini-gene construct revealed that the exon 7 acceptor splice site was replaced by a cryptic splice resulting in a transcript missing 64 bp of exon 7 (p.Val170Serfs*8). Our study confirms a pathogenic effect of a novel RPS7 variant in DBA associated with spontaneous remission in the mother and meningocele in her daughter, thus adding to the genotype-phenotype correlations in DBA.
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| 3. |
- Ali, Zafar, et al.
(author)
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Homozygous GRID2 missense mutation predicts a shift in the D-serine binding domain of GluD2 in a case with generalized brain atrophy and unusual clinical features
- 2017
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In: BMC Medical Genetics. - : Springer Science and Business Media LLC. - 1471-2350. ; 18:1
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Journal article (peer-reviewed)abstract
- BACKGROUND: Spinocerebellar ataxias comprise a large and heterogeneous group of disorders that may present with isolated ataxia, or ataxia in combination with other neurologic or non-neurologic symptoms. Monoallelic or biallelic GRID2 mutations were recently reported in rare cases with cerebellar syndrome and variable degree of ataxia, ocular symptoms, hypotonia and developmental delay.CASE PRESENTATION: We report on a consanguineous family with autosomal recessive childhood onset of slowly progressive cerebellar ataxia and delayed psychomotor development in three siblings. MRI of an adult and affected family member revealed slightly widened cerebral and cerebellar sulci, suggesting generalized brain atrophy, and mild cerebellar atrophy. Using whole exome sequencing we identified a novel homozygous missense variant [c.2128C > T, p.(Arg710Trp)] in GRID2 that segregates with the disease. The missense variant is located in a conserved region encoding the extracellular serine-binding domain of the GluD2 protein and predicts a change in conformation of the protein.CONCLUSION: The widespread supratentorial brain abnormalities, absence of oculomotor symptoms, increased peripheral muscle tone and the novel missense mutation add to the clinical and genetic variability in GRID2 associated cerebellar syndrome. The neuroradiological findings in our family indicate a generalized neurodegenerative process to be taken into account in other families segregating complex clinical features and GRID2 mutations.
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| 4. |
- Ali, Zafar, et al.
(author)
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Novel SACS mutations associated with intellectual disability, epilepsy and widespread supratentorial abnormalities
- 2016
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In: Journal of the Neurological Sciences. - : Elsevier BV. - 0022-510X .- 1878-5883. ; 371, s. 105-111
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Journal article (peer-reviewed)abstract
- We describe eight subjects from two consanguineous families segregating with autosomal recessive childhood onset spastic ataxia, peripheral neuropathy and intellectual disability. The degree of intellectual disability varied from mild to severe and all four affected individuals in one family developed aggressive behavior and epilepsy. Using exome sequencing, we identified two novel truncating mutations (c.2656C>T (p.Gln886*)) and (c.4756_4760delAATCA (p.Asn1586Tyrfs*3)) in the SACS gene responsible for autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). MRI revealed typical cerebellar and pontine changes associated with ARSACS as well as multiple supratentorial changes in both families as likely contributing factors to the cognitive symptoms. Intellectual disability and behavioral abnormalities have been reported in some cases of ARSACS but are not a part of the characteristic triad of symptoms that includes cerebellar ataxia, spasticity and peripheral neuropathy. Our combined findings bring further knowledge to the phenotypic spectrum, neurodegenerative changes and genetic variability associated with the SACS gene of clinical and diagnostic importance.
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| 5. |
- Arzoo, Pakeeza Shaiq, et al.
(author)
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WNT10A Mutations Account for 1/4 of Population- Based Isolated Oligodontia and Show Phenotypic Correlations
- 2014
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In: American Journal of Medical Genetics. Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 164:2, s. 353-359
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Journal article (peer-reviewed)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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| 6. |
- Azhar, Aysha, et al.
(author)
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A novel mutation in Lysophosphatidic Acid Receptor 6 gene in autosomal recessive hypotrichosis and evidence for a founder effect
- 2012
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In: EJD. European journal of dermatology. - : John Libbey Eurotext. - 1167-1122 .- 1952-4013. ; 22:4, s. 464-466
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Journal article (peer-reviewed)abstract
- Mutations in the lysophosphatidic acid receptor 6 (LPAR6) gene cause localized autosomal recessive hypotrichosis. We report six consanguineous families from Pakistan with segregating hypotrichosis localized to the scalp. Genetic investigation using polymorphic microsatellite markers revealed homozygosity spanning the LAH3 locus on chromosome 13 in affected individuals of all six families. Sequence analysis of the LPAR6 gene showed a novel insertion resulting in a frameshift and a premature termination (p.I194FfsX11) in affected members of one family. In the remaining five families we identified a previously described missense mutation (p.G146R) in a homozygous state in affected members. The closest flanking polymorphic marker showed an identical allele size in the five families segregating with the p. G146R mutation, supporting a single origin of this variation. These findings extend the spectrum of known LPAR6 mutations and suggest a founder effect of the p. G146R mutation in the Pakistani population.
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| 7. |
- Bergendal, Birgitta, et al.
(author)
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Abnormal primary and permanent dentitions with ectodermal symptoms predict WNT10A deficiency
- 2016
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In: BMC Medical Genetics. - : Springer Science and Business Media LLC. - 1471-2350. ; 17
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Journal article (peer-reviewed)abstract
- Background: The WNT10A protein is critical for the development of ectodermal appendages. Variants in the WNT10A gene may be associated with a spectrum of ectodermal abnormalities including extensive tooth agenesis. Methods: In seven patients with severe tooth agenesis we identified anomalies in primary dentition and additional ectodermal symptoms, and assessed WNT10A mutations by genetic analysis. Results: Investigation of primary dentition revealed peg-shaped crowns of primary mandibular incisors and three individuals had agenesis of at least two primary teeth. The permanent dentition was severely affected in all individuals with a mean of 21 missing teeth. Primary teeth were most often present in positions were succedaneous teeth were missing. Furthermore, most existing molars had taurodontism. Light, brittle or coarse hair was reported in all seven individuals, hyperhidrosis of palms and soles in six individuals and nail anomalies in two individuals. The anomalies in primary dentition preceded most of the additional ectodermal symptoms. Genetic analysis revealed that all seven individuals were homozygous or compound heterozygous for WNT10A mutations resulting in C107X, E222X and F228I. Conclusions: We conclude that tooth agenesis and/or peg-shaped crowns of primary mandibular incisors, severe oligodontia of permanent dentition as well as ectodermal symptoms of varying severity may be predictors of biallelic WNT10A mutations of importance for diagnosis, counselling and follow-up.
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| 8. |
- Bergendal, Birgitta, et al.
(author)
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Isolated Oligodontia Associated With Mutations in EDARADD, AXIN2, MSX1, and PAX9 Genes
- 2011
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In: American Journal of Medical Genetics Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 155:7, s. 1616-1622
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Journal article (peer-reviewed)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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| 9. |
- Clewemar, Pantelis, et al.
(author)
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Expanding the phenotypic spectrum of osteogenesis imperfecta type V including heterotopic ossification of muscle origins and attachments
- 2019
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In: Molecular Genetics & Genomic Medicine. - : Wiley. - 2324-9269. ; 7:7
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Journal article (peer-reviewed)abstract
- BackgroundOsteogenesis imperfecta (OI) is a clinical and genetic heterogeneous group of connective tissue disorders, characterized by bone fragility and a propensity to fracture.MethodsIn this report we describe the clinical phenotype of two patients, a 28‐year‐old woman and her mother (54 years old), both with a history of short stature and multiple fractures.ResultsExome sequencing revealed the recurring IFITM5:c.‐14 C>T variant causing OI type V. Both patients had several fractures during childhood. CT‐scan and scintigraphy showed ossification of the origin and attachment of muscles and hypertrophic callus formation.ConclusionOssification of the origin and attachment of muscles seems to be part of the phenotype in patients with OI type V.
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| 10. |
- Cui, Chang-Yi, et al.
(author)
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Frizzled6 Deficiency Disrupts the Differentiation Process of Nail Development
- 2013
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In: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 133:8, s. 1990-1997
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Journal article (peer-reviewed)abstract
- Nails protect the soft tissue of the tips of digits. The molecular mechanism of nail (and claw) development is largely unknown, but we have recently identified a Wnt receptor gene, Frizzled6 (Fzd6), that is mutated in a human autosomal-recessive nail dysplasia. To investigate the action of Fzd6 in claw development at the molecular level, we compared gene expression profiles of digit tips of wild-type and Fzd6(-/-) mice, and showed that Fzd6 regulates the transcription of a striking number of epidermal differentiation related genes. Sixty-three genes encoding keratins (Krts), keratin-associated proteins, and transglutaminases (Tgms) and their substrates were significantly downregulated in the knockout mice. Among them, four hard Krts, Krt86, Krt81, Krt34, and Krt31; two epithelial Krts, Krt6a and Krt6b; and Tgm 1 were already known to be involved in nail abnormalities when dysregulated. Immunohistochemical studies revealed decreased expression of Krt86, Krt6b, and involucrin in the epidermal portion of the claw field in the knockout embryos. We further showed that Dkk4, a Wnt antagonist, was significantly downregulated in Fzd6(-/-) mice along with Wnt, Bmp, and Hh family genes; and Dkk4 transgenic mice showed a subtly but appreciably modified claw phenotype. Thus, Fzd6-mediated Wnt signaling likely regulates the overall differentiation process of nail/claw formation.
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