MOLECULAR AND POPULATION GENETIC ANALYSES OF BETA-THALASSEMIA IN TURKEY

In this report we describe the molecular analysis of 795 chromosomes d erived from unrelated Turkish beta-thalassemia and sickle cell anemia carriers identified in hematology clinics in Istanbul, Ankara, Izmir, Adana, and Antalya, The determination of the molecular pathology of 75 4 beta-thalassemia and 42 abnormal hemoglobin genes and analysis of th e frequency distribution in six distinct regions of Turkey was accompl ished, The experimental strategy, based on PCR amplification of the be ta-globin gene, included dot-blot hybridization with 18 probes specifi c for the Mediterranean populations, denaturing gradient gel electroph oresis, and genomic sequencing. When the regional results are compared with the overall frequency of mutations in the country, it is observe d that the frequencies in the western and southern parts of Turkey are in good accordance with the overall distribution, whereas the norther n and eastern parts have a more region/population-specific profile wit h some rare mutations having a significantly high occurrence in these regions, Further evaluation of the data with respect to region- or pop ulation-dependent differences will contribute to a better understandin g of the mechanisms leading to the marked genetic heterogeneity in Tur key, but could also be extremely valuable in facilitating rapid identi fication of mutations in families at risk for different hemoglobinopat hies. (C) 1998 Wiley-Liss, Inc.