MOLECULAR SPECTRUM OF β-THALASSEMIA IN THE IRANIAN PROVINCE OF HORMOZGAN

Abstract

Prevention of β-thalassemia implies knowledge of the molecular spectrum occurring in the population at risk. This knowledge is necessary, especially when a prevention protocol is applied to a multiethnic population. For this purpose, we have recently analyzed a large population of Iranian patients living in the Province of Hormozgan in Iran, and a small group of Iranian patients living in The Netherlands. We have found a different mutation spectrum in both populations as compared to the data obtained by other authors for the Iranian regions of Tehran, Fars, Sistan Balouchestan, Bushehr, and Khouzestan. The IVS-I-5 (G → C) is the most frequent mutant in the province of Hormozgan (69%), followed by the IVS-II-1 (G → A) (9.6%), while the IVS-I-1 (G → A) was the most frequent defect found in the Iranian population sample in The Netherlands. The IVS-II-745 (C →G) mutation in cis with the 5′UTR (untranslated region) +20 (C → T) transition was observed in two unrelated, transfusion-dependent homozygotes, living in the Hormozgan Province where, in contrast with populations living in other provinces of Iran, no IVS-I-110 (G → A) or IVS-I-1 (G → A) mutations were found. We report the molecular spectra of our population samples and compare them with the mutation spectra observed in the Iranian populations by other authors. We discuss the severe phenotype of the patients homozygous for the IVS-II-745 (C → G) mutation, linked in cis to the 5′UTR +20 (C→ T) transition. Molecular analysis using commercial kits is briefly compared with denaturing gradient gel electrophoresis, emphasizing the value of a rapid method of detection for molecular defects in areas where many mutations occur.