Hemoglobin variants, hematological parameters and β-globin gene cluster haplotypes in an isolated Amerindian group from the Orinoco River Delta

Background: Several previous studies reported that the Venezuelan Warao Indians presented unusual genetic characteristics.Aim: The present study checked previous reports of a high frequency of hereditary persistence of fetal hemoglobin (HPFH) and examined other hematological traits.Subjects and methods: Standard hematology, electrophoresis on cellulose acetate, fetal hemoglobin alkali denaturation, γ-globin chain, DNA amplification and sequencing, and denaturing gradient gel electrophoresis determinations were performed in 269 individuals living in two localities of the Orinoco River Delta.Results: Two βs genes, in apparently non-related individuals, were found. HPFH, detected in this same population of Warao Indians 25 years ago, was present in heterozygous form in five individuals from a large kindred, with hemoglobin F levels ranging from 3.7% to 8%, and with a pancellular distribution. The HPFH mutation was of the deletional type. β-globin gene haplotypes were determined by direct counting (through fa...