Prenatal diagnosis of haemophilia-A: a basis for the Pakistani families.

OBJECTIVE To determine the feasibility of a PCR based strategy for prenatal diagnosis of Haemophilia-A in Pakistani Families. DESIGN Prospective. SETTING Department of Haematology, Armed Forces Institute of Pathology, Rawalpindi. SUBJECTS Five families with at least one child affected with Haemophilia-A. Each family comprised of father, mother, affected child and fetus when present. MAIN OUTCOME MEASURES Short Tandem Repeat (STR) analysis in the Intron 22 of factor VIII gene. RESULTS PCR based analysis of the STR in intron 22 of factor VIII gene showed that the marker was informative in 4/5 study families and could be used in these families for the prenatal diagnosis of Haemophilia-A. In two families prenatal diagnosis was carried out by Chorionic Villus Sampling at 10-13 weeks gestation and the results in both the cases showed a carrier female fetus. CONCLUSION Linkage based prenatal diagnosis of Haemophilia-A by an intragenic STR marker is feasible in most of the Pakistani families. The long term response of the Haemophiliac families to the availability of prenatal diagnosis remains to be seen. The STR marker can also be used for carrier detection of female subjects in the affected families.