中华皮肤科杂志 ›› 2003, Vol. 36 ›› Issue (4): 189-191.

• 论著 • 上一篇    下一篇

A型着色性干皮病中XPAC基因的无义突变

杨勇, 卜定方, 汪科, 涂平, 朱学骏   

  1. 北京大学第一医院皮肤性病科 100034
  • 收稿日期:2002-04-06 出版日期:2003-04-15 发布日期:2003-04-15
  • 基金资助:
    北京大学医学部“创建世界一流大学行动计划”青年启动基金资助课题

Nonsense Mutation of XPAC Gene in a Pedigree with Xeroderma Pigmentosum Group A

YANG Yong, BU Ding-fang, WANG Ke, TU Ping, ZHU Xue-jun   

  1. Department of Dermatology, First Hospital, Peking University, Beijing 100034, China
  • Received:2002-04-06 Online:2003-04-15 Published:2003-04-15

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摘要： 目的 检测国内一A型着色性干皮病家系中XPAC基因的突变。方法 PCR扩增XPAC基因的全部外显子,并行DNA测序。针对所发现的突变以DdeⅠ内切酶行限制性片段长度多态性(RFLP)分析。结果 PCR结合DNA测序发现患者XPAC基因第5外显子存在异常:第631位碱基由胞嘧啶突变为胸腺嘧啶,使第211位氨基酸由精氨酸变为终止密码(R211X),导致其编码的XPA蛋白缺失了C端的63个氨基酸。其父母皆为杂合子。RFLP结果证实了此突变的存在。结论 本A型着色性干皮病家系中存在XPAC基因突变,突变致使XPA蛋白功能缺陷,DNA损伤的修复功能受损,导致临床上出现皮肤老化和癌变。

关键词: 干皮病,着色性, 基因, 突变

Abstract: Objective To determine XPAC gene mutation in a Chinese pedigree with xeroderma pigmentosum group A.Methods All exons of XPAC gene were analyzed by PCR-DNA sequencing in the pedigree.The mutations were confirmed by restriction fragment length polymorphism(RFLP).Results By PCR-DNA sequencing,a nonsense mutation of C631T was identified which caused R211X substitution in exon 5 of XPAC gene.The mutated gene encoded a defective XPA protein truncated by63 amino acids in C-terminus.The parents were all heterozygotes.The results were confirmed by RFLP.Conclusions A nonsense mutation is found in XPAC gene of a pedigree of xeroderma pigmentosum group A.This mutation may impair XPA protein function of DNA repair,and as a consequence,cause skin aging and carcinogenesis.

Key words: Xeroderma pigmentosum, Genes, Mutation