A recurrent missense mutation of keratin 1 gene in a Chinese family with epidermolytic hyperkeratosis (severe palmoplantar hyperkeratosis, type 1)

Purpose: To demonstrate the underlying genetic defect that contribute to inherited cataract in a northern Chinese pedigree. Methods: The study recruited a family pedigree with a diagnosis of bilateral coronary cataract with blue punctate opacities. Fourteen family members and 100 healthy volunteers were enrolled. DNA sample of the proband in this family were analyzed by high-throughput sequencing, which was then demonstrated by Sanger sequencing in the remained people in the family and 100 controls. The functional effect of mutant genes was investigated via bioinformatics analysis, including Polymorphism Phenotyping version2 (PolyPhen-2), Protein Variation Effect Analyzer (PROVEAN v1.1.3) Scale-Invariant Feature Transform (SIFT), and Mutation Taster. Results: In this three-generation family, a novel heterozygous mutation was found in the kinase domain of CRYBA1 gene (c.340C > T, p.R114C), which was only detected in patients in the family with inherited cataract and were not detected in the remained people in the family nor in normal people. The pathogenic effect of the mutation was verified via bioinformatics analysis. Conclusion: Our study presented the molecular experiments to confirm that a novel missense mutation of c.340 C > T located in exon 4 of CRYBA1 gene results in a bilateral coronary cataract with blue punctate opacities, which enriches the mutation spectrum of CRYBA1 gene in inherited cataract and deepens the understanding of the pathogenesis of inherited cataract.

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Novel missense mutation of SASH1 in a Chinese family with dyschromatosis universalis hereditaria

BMC Medical Genomics ◽

10.1186/s12920-021-01014-w ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Lu Cao ◽

Ruixue Zhang ◽

Liang Yong ◽

Shirui Chen ◽

Hui Zhang ◽

...

Keyword(s):

Missense Mutation ◽

Sequence Alignment ◽

Multiple Sequence Alignment ◽

Molecular Genetic ◽

Family Members ◽

Clinical Manifestations ◽

Gene Mutations ◽

Mendelian Inheritance ◽

Chinese Family ◽

Multiple Sequence

Abstract Background Dyschromatosis universalis hereditaria (DUH) is a pigmentary dermatosis characterized by generalized mottled macules with hypopigmention and hyperpigmention. ABCB6 and SASH1 are recently reported pathogenic genes related to DUH, and the aim of this study was to identify the causative mutations in a Chinese family with DUH. Methods Sanger sequencing was performed to investigate the clinical manifestation and molecular genetic basis of these familial cases of DUH, bioinformatics tools and multiple sequence alignment were used to analyse the pathogenicity of mutations. Results A novel missense mutation, c.1529G>A, in the SASH1 gene was identified, and this mutation was not found in the National Center for Biotechnology Information Database of Short Genetic Variation, Online Mendelian Inheritance in Man, ClinVar, or 1000 Genomes Project databases. All in silico predictors suggested that the observed substitution mutation was deleterious. Furthermore, multiple sequence alignment of SASH1 revealed that the p.S510N mutation was highly conserved during evolution. In addition, we reviewed the previously reported DUH-related gene mutations in SASH1 and ABCB6. Conclusion Although the affected family members had identical mutations, differences in the clinical manifestations of these family members were observed, which reveals the complexity of the phenotype-influencing factors in DUH. Our findings reveal the mutation responsible for DUH in this family and broaden the mutational spectrum of the SASH1 gene.

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