[Long distance-PCR for detection of factor VIII gene inversion in patients with severe hemophilia A].

The aim of current study was to detect intron 22 inversion of factor Ⅷ gene in severe hemophilia A (HA) patients and screen the carriers of the gene inversion. Fifty five cases of severe HA were involved and factor Ⅷ gene inversion was detected and identified by long distance PCR (LD PCR) and 0.6% agarose gel electrophoresis. The 11 kb and 12 kb bands indicate the factor Ⅷ gene inversion and non inversion, respectively. Occurring of both 11 kb and 12 kb bands indicates a carrier of the inversion. The results showed that factor Ⅷ gene inversion existed in 22 out of 55 cases, which accounted for about 40% of total detected patients. Five carriers of factor Ⅷ gene inversion were diagnosed from the members in 15 families. In conclusion, LD PCR assay is a simple, rapid and accurate method for detection of factor Ⅷ gene inversion, and this approach is helpful in screening, carrier testing, and prenatal diagnosis of severe hemophilia A.