β-Thalassemia intermedia associated with homozygosity for the -87 (C→T) mutation in a Turkish family

We report on two siblings with β⁺-thalassemia intermedia. Molecular studies of the β-globin gene indicated that the patients are homozygous for the -87 (C→T) mutation. This genotype has not been previously described. Homozygosity for the -87 (C→T) mutation produces a mild form of β⁺- thalassemia associated with moderate Hb F elevation (26-38%) and highly elevated Hb A₂ (10-8.6%) levels, respectively. Hematological parameters of homozygous -87 (C→G) and -87 (C→A) mutations, and compound heterozygous patients with either C→T, C→G, or C→A at-87 and one of the severe β⁺- or β⁰-thalassemia mutations, are given for comparison.