A Comprehensive Narrative Review of Hemophilia A and B: Screening, Counselling, and Therapeutic Advances

A deficiency of factor VIII (FVIII) and factor IX (FIX) causes hemophilia A (HA) and hemophilia B (HB), respectively. These X-linked recessive disorders result from mutations in the F8 gene at Xq28 for HA and the F9 gene at Xq27 for HB on the X chromosome. These disorders, which lead to coagulation complications and prolonged bleeding, primarily affect men. Hemophilia A accounts for approximately 80% of all cases. The allele frequencies of three FVIII gene-linked markers—IVS7 nt 27 G/A SNP, Bcl-I/intron 18, and Hind-III/intron 19—were assessed using ARMS (amplification refractory mutation system) primers in 276 Indian women from unrelated families. The most feasible method to identify carriers in underdeveloped nations is indirect linkage analysis to detect a defective X chromosome. Using restriction fragment length polymorphism and polymerase chain reaction, 276 individuals from 203 families with male hemophilia A patients and 276 healthy participants were recruited at Sir Sunderlal Hospital, Varanasi. The participants were evaluated for the intron 18 Bcl-I, intron 19 Hind-III, and IVS7 nt 27 SNP markers. The Bcl-I, Hind-III, and IVS7 markers were heterozygous in 54%, 39%, and 13% of the women studied, respectively. The allele frequencies of IVS7 nt 27 "G"/"A," Bcl-I "T"/"A," and Hind-III "C"/"T" were 0.87/0.13, 0.47/0.54, and 0.62/0.38, respectively, in healthy women. The informativeness of families using the Bcl-I, Hind-III, and IVS7 markers was 57%, 45%, and 16%, respectively. The combined informativeness of these polymorphic sites was 67%. The present study demonstrates that the IVS7-SNP, Bcl-I, and Hind-III markers can effectively diagnose HA carriers in the Indian population.