弥漫性表皮松解性掌跖角化病两家系突变分析

目的: 检测弥漫性表皮松解性掌跖角化病两家系中KRT9基因的突变情况。方法: 收集各家系患者的临床资料，抽取家系患者、正常人及200名健康志愿者外周血并提取DNA，采用聚合酶链式反应(PCR)扩增KRT9基因全部外显子并进行sanger测序。结果:在两个家系所有患者的KRT9基因1号外显子均检测到c．487C＞T 错义突变(p．163Ｒ＞W)，家族未患病成员以及200名正常对照中未发现此突变。家系1中先证者的女儿和祖父除了掌跖角化过度外还出现了先天性指节垫和先天性指曲屈畸形，而家系2中所有患者并未出现该症状。结论: KRT9基因的c．487C＞T 错义突变是导致这两个表皮松解性掌跖角化病家系的遗传学病因，同一突变在不同家系或同一个家系的不同个体之间的临床表型存在差异。

Mutation detection in two epidermolytic palmoplantar keratosis families

Objective: To detect the mutation of KRT9 gene in two epidermolytic palmoplantar keratosis families. Methods: Clinical data of each family were collected. DNA was extracted from the peripheral blood of patients, normal people in two family and 200 healthy volunteers. All exons of KRT9 gene were amplified by polymerase chain reaction (PCR) and the product was performed by sanger sequencing. Results: A missense mutation c.487C>T (p.163R>W) was identified in exon 1 of KRT9 gene in all patients of both families. This missense mutation was not found in healthy family members and 200 normal controls. In family one, the daughter and grandfather not only manifested hyperkeratosis of the palmoplantar skins, but congenital knuckle pads and congenital flexion deformity, while all the patients in another family did not have this symptom. Conclusion: The missense mutation of 487C > T of the KRT9 gene is the genetic cause of these two families with epidermolytic palmoplantar keratosis. Clinical phenotypes caused by the same mutation among individual from different family or same family may be different.