Analysis of KRT9 gene mutation in Chinese Han population / 上海交通大学学报（医学版）

Objective • To explore the main mutation types and pathogenicity of the coding region of keratin 9 gene (KRT9) in Chinese Han population, and to provide reference information for the classification and prediction of clinical diagnosis of the disease with epidermolytic palmoplantar keratoderma (EPPK). Methods • 834 subjects were recruited from 278 families that were not affected by EPPK in the Chinese Han population. The mutations in the coding region of KRT9 gene were detected by using the next-generation sequencing (NGS)-based gene panel combined with Sanger sequencing. The pathogenicity analysis of variants was performed by using SIFT and Polyphen-2 prediction software. Results • A total of twelve KRT9 gene mutations were detected in the Chinese Han population based on 834 individuals from 278 families. Among the twelve different mutations, six synonymous mutations and six missense mutations were identified, respectively. The assessment of pathogenicity of KRT9 gene variants was analyzed by bioinformatics tools, such as SIFT and Polyphen-2 prediction, conservative analysis, and database query. Furthermore, these missense mutations were classified as benign or possibly benign variants. Conclusion • In this study, six missense mutations in the coding region of KRT9 gene exon were detected in the Chinese Han population. According to the American Society of Medical Genetics and Genomics (ACMG) variant classification guide, all the six variants were benign or possibly benign. However, previous reports have found that a KRT9 c.1216T>C (p.C406R) mutation was pathogenic in a pedigree with EPPK, which were inconsistent with our findings, and the pathogenicity of this mutation still has to be verified by further functional experiments.

Localization of the disease-causing gene coding for hereditary palmoplantar keratoderma / 基础医学与临床

Objective To identify a locus at chromosome coding for hereditary palmoplantar keratoderma of three Chinese pedigrees.Methods The genome scan was conducted with microsatellite markers on chromosome 12(D12S85、D12S368、D12S83、D12S345)and 17(D17S1868、D17S787、D17S1857、D17S798、D17S944、D17S949)respectively on the ABI 3100 Genetic Analyzer(Applied Biosystems).Two-point LOD score was calculated.Results The maximum two-point LOD score 6.59 and 5.96 at ?=0.1 were obtained at D17S1868 and D17S787 on chromosome 17q12～q21.It is an evidence of linkage between this disease and KRT9 which has been mapped within the region.Conclusion There is a locus responsible for this disease on chromosome 17q12～q21.