Sickle cell gene haplotypes in Relli and Thurpu Kapu populations of Andhra Pradesh.

We performed polymerase chain reaction analysis of 8 restriction-site polymorphisms in the beta-globin gene cluster to define haplotypes and provide hematological profiles of Relli and Thurpu Kapu caste populations in Andhra Pradesh, India. In all sickle cell homozygous subjects, the clinical manifestation of the disease is benign with elevated fetal hemoglobin levels (3.9%-21.1%). Clinical symptoms in some of the sickle cell homozygous subjects include jaundice, leg ulcers, and splenomegaly. Molecular analysis of the sickle cell gene (HBB*S) reveals the presence of the ubiquitous Arab-Indian haplotype in both populations. We encountered, for the first time, a rare, atypical haplotype ((+)-------) in a sickle cell homozygous individual of the Thurpu Kapu population, presumably the result of gene conversion.