摘要目的血友病A(HA)是FⅧ基因缺陷导致的X连锁隐性遗传性疾病。本研究尝试简单、快速并易于推广的基因诊断方法学，完善HA携带者检测和产前诊断体系。方法　应用长距离PCR进行内含子22倒位检测，并对FⅧ基因内的BclⅠRFLP位点和两个STR位点，以及FⅧ基因外的St14 VNTR位点进行连锁分析。结果　共对21个家系进行内含子22倒位检测，发现存在倒位的家系占47.6%。利用此分子缺陷进行3例产前诊断。进一步联合4个基因内和基因外多态性位点进行遗传连锁分析，总诊断率达94.7%。结论　存在倒位的家系可依此进行直接诊断，长距离PCR使其更为快速简便。对于无倒位的家系，利用基因多态性进行遗传连锁分析较为有效可行。

abstractsObjective To establish an effective laboratory examination system for carrier detection and prenatal diagnosis of haemophilia A (HA) with a variety of molecular biological methods which are simple, rapid and easy to use. Methods Detection of inversion involving intron 22 in the FⅧ gene was completed by long distance polymerase chain reaction (PCR) and linkage analysis was performed by using several genetic polymorphisms including an intragenic BclⅠ RFLP, 2 STRs and an extragenic St14 VNTR. Results Intron 22 inversion was observed in 10 out of the 21 (47.6%) pedigrees examined. Prenatal diagnosis was completed in 3 pedigrees. A further combination of the four intragenic and extragenic polymophic loci gave an informative rate of 94.7%. Conclusions Female relatives in HA families with inversion can be detected with direct diagnostic procedure. The application of long distance PCR makes the detection much more simple and rapid. For families without inversions, it is easier and more cost-effective to undertake linkage analysis of genetic polymorphism based on PCR.