Prenatal diagnosis of haemophilia A by the polymerase chain reaction using the intragenic hind III polymorphism.

A method is described which uses the Hind III polymorphism in intron 19 of the factor VIII gene for genomic family analysis and prenatal diagnosis by the polymerase chain reaction. The primers derived from the exon 19 and 20 sequences allow amplification of the whole intron 19 resulting in a 730 bp fragment. Hind III restriction of this fragment provides fragments of 250 bp or 160 bp and 90 bp respectively, specific for the intragenic Hind III polymorphism. The constant 480 bp fragment can be used as an internal control to circumvent misdiagnosis due to incomplete or failure of restriction. Using this method a prenatal diagnosis of haemophilia A in the first trimester of pregnancy is demonstrated.