中文摘要：

目的绘制5个表皮松解性掌跖角化症（EPPK）家系的致病突变谱。应其中3个家系的要求,实施相关的产前DNA诊断。方法分别抽取5个家系相关成员的抗凝外周血,纯化基因组DNA。PCR扩增EPPK的主要致病基因角蛋白9（KRT9）的编码氨基酸的全部7个外显子（第1-7外显子）及其相邻DNA区域的序列,Sanger测序鉴定基因突变。用AS-PCR法验证所发现的KRT9基因突变。抽取3个家系的相关孕妇的羊水,纯化胎儿基因组DNA,PCR、Sanger测序和AS-PCR法确定胎儿的KRT9基因型。结果 2个EPPK家系的致病基因KRT9突变为最常见的突变：位于第1外显子的c.487C〉T（p.Arg163Trp）杂合性错义突变;其余3个家系的杂合性错义突变分别为：c.482A〉G（p.Asn161Ser）、c.488G〉A（p.Arg163Gln）和c.566A〉G（p.Tyr167Cys）。遗憾的是,3个家系的产前DNA诊断均显示胎儿存在对应的KRT9基因突变,表明为患病。结论对于临床上疑似为EPPK的家系,可快速筛查KRT9基因突变,辅助临床精准诊断本病。在首先确定了家系的基因突变谱之后,可行羊膜穿刺术或PGD,以预防EPPK患儿的出生,实现优生优育。

英文摘要：

Objective：To investigate the KRT9 gene mutation spectrum of five epidermolytic palmoplantar keratoderma（EPPK）pedigrees,and to perform the prenatal DNA diagnosis at the request of 3 families. Methods：Venous blood of the family members was collected,and genomic DNA was purified. After amplifying the sequences of all 7 coding exons and their adjacent DNA regions by PCR,Sanger sequencing was performed to reveal the potential KRT9 mutant. Then,AS-PCR was carried out to verify the mutation. For prenatal DNA diagnosis,amniotic fluid was collected from the pregnant woman in the pedigree first,then fetal genomic DNA was extracted. PCR,Sanger sequencing and AS-PCR were used to test the genotype of the fetus. Results：Among 5 EPPK pedigrees,c.487C〉T（p.Arg163Trp）,the most common heterogenous mutant in KRT9,was found in 2 pedigrees;other heterogenous mutants were c.482A〉G（p.Asn161Ser）,c.488G〉A（p.Arg163Gln）and c.566A〉G（p.Tyr-167Cys）,respectively. Unfortunately,the results of prenatal DNA diagnosis showed that fetuses from the three families had the corresponding KRT9 mutation. Conclusions：For the suspected EPPK patient and his or her family,KRT9 gene testing can be applied rapidly to help the clinical precision diagnosis. Once the KRT9 mutant was identified,amniocentesis or preimplantation genetic diagnosis（PGD）could be used to predict the status of fetus in the family in order to realize birth health.