A rare mutation [IVS-I-130 (G-A)] in a Turkish beta-thalassemia major patient

Here we describe the identification of the rare beta-thalassemia mutation I VS-I-130 (G-A) for the first time in Turkey. The hematological evaluation o f the patient showed classical signs of P-thalassemia major requiring regul ar blood transfusions every 30-35 days. DNA analysis was carried out using reverse dot-blot hybridization and restriction endonuclease digestion, as w ell as genomic sequencing. The patient was found to be heterozygous for the IVS-I-6 (T-C) and IVS-I-130 (G-A) mutations. In order to deduce a possible origin for the IVS-I-130 (G-A) mutation, the sequence polymorphisms in the DNA of the patient and her family were characterized. The method included the analysis of nine polymorphic nucleotides and the hypervariable microsat ellite of composite sequence (AT)(x)T-y 5' to the beta-globin gene by DNA s equencing. The sequence haplotype (HT4) carrying the IVS-I-130 (G-A) mutati on is also observed in Algeria. This favors a Northeastern African origin f or this allele. The observed results agree well with a recent introduction of this mutation to Turkey from Egypt toward the end of the 19th century. A m. J. Hematol. 63:223-225, 2000. (C) 2000 Wiley-Liss, Inc.