CACNA1S基因突变致低钾周期性麻痹的产前基因诊断

目的对CACNA1S基因R1239H突变导致的低钾周期性麻痹（HoKPP1型）家系中的1例中期妊娠者进行产前基因诊断,从而预防HoKPP患儿出生。方法患者于16孕周在B超下进行羊膜囊穿刺,抽取羊水10 mL,提取羊水细胞基因组DNA。选择3个多态性STR位点,D13S317、D8S1179和D16S539,排除母体细胞的污染。在此基础上对CAC-NA1S基因外显子30进行扩增,PCR产物进行正、反向测序。结果 STR多态性位点分析,证明无母体细胞污染,胎儿CACNA1S基因30外显子测序结果显示,胎儿带有和母亲同样的CACNA1S基因突变R1239H。结论对于有HoKPP风险的胎儿进行产前基因诊断非常重要,可以明确胎儿基因型,预防患儿出生。

Prenatal molecular diagnosis of hypokalemic periodic paralysis caused by CACNA1S mutation

Objective:To prenatal molecular diagnosis a mid-pregnancy who has hypokalemic periodic paralysis type 1(HoKPP type 1)caused by a mutation in gene CACNA1S(R1239H)in order to preventing the occurrence of HoKPP.Methods:Puncture ammiotic sac under the help of type-B ultrasonic at 16 Gestational age to extract amniotic fluid 10 mL then extract genome DNA of amniotic fluid cell.Choose three STR polymorphic loci,D13S317,D8S1179 and D16S539,excluding maternal cell contamination.On this basis,amplified CACNA1S exon 30 by PCR,and sequenced forword and reverse of PCR products.Results:Analysis of these STR polymorphic loci,there are no maternal cell contamination,Fetal CACNA1S gene sequencing of exon 30 showed that the fetal carried the same mutation as the mother.Conclusion:It is important for the fetus who has high probability to suffer HoKPP to have a prenatal molecular diagnosis,in order to understand the genotype and ensure the diagnosis of fetal.