Restriction fragment length polymorphism (RFLP) of the X chromosome linked glucose-6-phosphate dehydrogenase (G6PD) locus in India.

STUDY: Haplotypes linked to glucose-6-phosphate dehydrogenase (G6PD) genotypes were defined by studying six intragenic restriction fragment length polymorphisms (RFLPs) in 141 G6PD deficient and 252 normal chromosomes. RESULTS: Only four of the 64 possible haplotypes were observed, indicating marked linkage disequilibrium. All the G6PD deficient mutations were associated with either haplotype I or VII, which are similar to the common G6PD B variant observed in the present study except the G6PD Namoru mutation which corresponded to mainly haplotype VIIa where a Nla III restriction site was created due to this mutation. CONCLUSION: The limited number and low haplotype diversity probably indicates a strong selective pressure on the G6PD gene.