Molecular characterization of haemophilia A & B in Indians

Forty-seven haemophilia A patients from 43 pedigrees and 34 haemophilia B p atients from 31 pedigrees were screened for the presence of mutations by So uthern blotting using factor Vm and IX cDNA and genomic DNA probes. Three d eletions and two restriction site variants were detected among 47 haemophil ia A patients and one deletion and two restriction site variants were detec ted in 34 haemophilia B patients. Overall, the frequency of mutations in ha emophilia A was 10.6%; the frequency of deletions was 6.4% and that of poin t mutations was 4.2%. In haemophilia B, the frequency of mutations detected was 9%; deletions 9% and point mutations 6%. The present report? the first from India, shows that like other earlier pub lished reports from Europe and the United States? mutations in haemophilia are heterogeneous, and that RFLP using Southern blotting did not detect mos t of the mutations in this disorder and is an insensitive and inefficient p rocedure.