Major beta-globin gene mutations in eastern India and their associated haplotypes.

324 alleles of the beta-globin gene from unrelated thalassaemia patients native to the eastern region of India (mainly from the state of West Bengal) were analysed for beta-globin gene mutations by the amplification refractory mutation system (ARMS). The major mutations that were detected are IVS-1 pos 5 (G-C), codon 26 (G-A) and codon 30 (G-C) with frequencies of 0.45, 0.33 and 0.05, respectively. Haplotype analysis revealed a very strong linkage disequilibrium of IVS-1 pos 5 (G-C) with one particular haplotype. HbE was found to be associated with two major haplotypes. Codon 30 (G-C) was associated with a haplotype that is the same as that found in the African population. Haplotype associated with codon 8/9 (+G) was the same as that found in northwest India. These findings have implications for the use of molecular diagnosis for genetic counselling and prenatal diagnosis of beta-thalassaemia in this region.