重型血友病A凝血因子Ⅷ第1内含子倒位的基因检测

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

目的 在中国重型血友病A（haemophilia A，HA）患者中筛查凝血因子Ⅷ（factorⅧ，FⅧ）基因第1内含子倒位，并对受累患者家系成员行携带者检查和产前基因诊断。方法对重型HA患者（FⅧ：C〈1％）采用长距离PCR法首先筛查第22内含子倒位，对第22内含子倒位阴性的应用双管多重PCR法进行第1内含子倒位检测，对第1内含子倒位阳性患者的女性家属进行携带者检测，对女性携带者所孕胎儿进行产前检测。用基因连锁分析和DNA测序法加以验证。结果从247例重型HA患者中共检测出118例第22内含子倒位和7例第1内含子倒位，第1内含子倒位突变在中国重型HA人群中的发病率约为2．8％；随访到的两个受累患者家系A和B中各检出6名和2名女性携带者，家系A中产前检出1名第1内含子倒位受累胎儿。结论采用双管多重PCR法可以直接检测凝血因子Ⅷ第1内含子倒位突变，完善了重型血友病A家系携带者检测和产前诊断。

Objective Screening the intron 1 inversion of factor Ⅷ （F Ⅷ ） in the population of severe haemophilia A（HA） in China and performing carrier detection and prenatal diagnosis, Methods Using LD- PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% （7/247）. Six women from family A and 2 from family I3 were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.