OBJECTIVETo improve inversion-polymerase chain reaction (I-PCR) in detection of factor VIII (FVIII) intron 22 inversion for gene diagnosis and prenatal diagnosis of hemophilia A (HA).

METHODSThe modified I-PCR was applied to detect FVIII intron 22 inversion in 8 families with HA. The prenatal diagnosis was performed for 2 pregnant women in the families. The fetal blood samples were obtained by cordocentesis at 22 and 26 weeks gestation respectively.

RESULTSFour of 8 HA families were diagnosed to be FVIII intron 22 inversion. Two fetuses were identified to be normal and one of them was born normal.

CONCLUSIONThe modified I-PCR enables the gene diagnosis and prenatal diagnosis of FVIII intron 22 inversion more accurately and rapidly.