Detection of intron 22 inversion type I and II of factor VIII gene in female carriers of hemophilia a using Inverse shifting PCR (IS-PCR) method

Hemophilia type A is the most common X-linked recessive bleeding disorder, which 45-50% of the cases are caused by intron 22 inversion of factor 8 gene. Carrier detection for prenatal diagnosis in affected families can be effective in order to reduce the spread of disease. Since the linkage analysis for detecting carriers is only possible in families with a family history of hemophilia A, therefore IS-PCR method was chosen as a convenient and reliable method for carrier detection of intron 22 inversion mutation even in sporadic cases of hemophilia A. This study was performed on families of hemophilia A patients with intron 22 inversion. After extracting DNA from peripheral blood leukocytes, IS-PCR technique was used to identify intron 22 inversion mutation types 1 and 2. Among the 9 cases that were analyzed for carrier status by IS-PCR, the results showed that 22/2% were without abnormal allele and 77/8% were carriers of intron 22 inversion mutation. Using Inverse Shifting PCR is a precise, rapid and reliable method for assessing rearrangements related to intron 22 inversion mutation type 1 and 2 for detecting hemophilia A carriers.