Use of factor IX intragenic recombinant DNA probes for evaluation of carrier status in haemophilia B families of Irish Origin

Two intragenic recombinant DNA probes derived from segments of the factor IX gene have been used to investigateTaql, Ddel and Xmnl restriction fragment length polymorphisms (RFLPs) in DNA from two Irish haemophilia B families.Xmnl and Taql polymorphisms were informative, permitting direct evalu-ation of carrier status in four females. In one family, the molecular basis for haemophilia B was a deletion removing a portion, or all of the factor IX gene.