In the West, linkage analysis with Bcl I, Xba I and Intron 13 or 22 VNTR markers and inversion 22 offers a good tool for carrier detection of hemophilia A in India.
Postulating that the combined use of all the available intragenic and extragenic markers can render such diagnoses more frequently feasible and more reliable, we carried out ten first-trimester prenatal diagnoses in male fetuses at risk for hemophilia A by DNA analysis of chorionic villus employing in combination the intragenic Bcl I polymorphism and the St 14 (DXS 52) or DX 13 (DXS 15) extragenic probes.