The Effects of Polymorphisms on Biochemical Parameters of Iron Status in Arab Beta-Thalassemia Patients.

In this study, the potential effect of three gene polymorphisms (C282Y, H63D and S65C) and the A77D polymorphism on iron balance was investigated in 234 subjects (91 Arab beta-thalassemia major (BTM) patients, 34 beta-thalassemia trait (BTT) individuals and 109 health controls). Genotyping was done using restriction-fragment-length polymorphism and direct-sequencing. Serum-iron, total iron binding capacity, transferrin and ferritin were estimated in all BTT and BTM, and in 65 healthy controls. H63D was the only polymorphism detected in our cohort. Allele frequency was 13% in both BTM and BTT and 10% in controls with no significant difference. Serum iron, ferritin and transferrin saturation were significantly higher in normal males heterozygous for H63D as compared to homozygous wild-type males. Ferritin was significantly higher in BTT males with or without H63D polymorphism when compared to the healthy males with H/H genotype. No such difference was observed between H/H versus H/D BTT subgroups. We conclude that H63D is the only significant hemochromatosis-associated polymorphism in the Arabian Gulf region. The heterozygous state of H63D may significantly alter iron parameters in normal males. In BTT, it appears that the beta-thalassemia allele has an overriding influence on ferritin values, and this generally manifest in males.