FACTOR-VIII GENE DELETIONS IN HEMOPHILIA-A PATIENTS IN CZECHOSLOVAKIA

Genomic DNA from 90 Czechoslovak haemophilia A patients from 81 pedigrees was analysed by Southern blotting and hybridization with factor VIII cDNA probes. Three partial deletions of the factor VIII gene were identified and characterized: a 4.8 kilobase (kb) deletion eliminating exon 10 in one patient with severe haemophilia A without inhibitor, a 6.1 kb deletion eliminating the 3' part of intron 13 and the 5' part of exon 14 in two related severe haemophiliacs, but only one of them produced inhibitor, and a 4.6 kb deletion eliminating the 3' part of intron 13 and the 5' part of exon 14 in a severe haemophiliac with high-titre inhibitor. Besides these three deletions, three different restriction site variants without apparent loss of DNA sequence were found.