β-Thalassemia mutations and hemoglobinopathies in Adana, Turkey: results from a single center study

β-Thalassemia and hemoglobinopathies are common genetic disorders in Turkey and in this retrospective study our aim was to determine the frequency of β-thalassemia and hemoglobinopathies in Adana, which is one of the biggest cities located in the southern part of Turkey.

Data from 3000 individuals admitted to Seyhan Hereditary Blood Disorders Center in Adana were evaluated. The blood samples were collected into EDTA-containing tubes and hematological parameters were analyzed using an automatic cell counter. High performance liquid chromatography technique was used to determine the type of hemoglobin. Molecular screening of the β-globin gene was performed with β-Globin StripAssay.

Of 3000 cases, 609 were diagnosed as β-thalassemia or hemoglobinopathy. We have found that the rates of occurrence of β-thalassemia and hemoglobinopathies are 13.46% and 6.83% respectively in this area. We have identified 18 different β-thalassemia mutations and three separate abnormal hemoglobins: HbS, HbD Los Angeles, and HbE. In molecular analyses, β-thalassemia gene mutations of IVSI.110 (G > A), codon 8 (-AA), IVSI.1 (G > A), IVSI.6 (T > C), -30 (T > A), IVSII.1 (G > A), codon 39 (C > T), codon 44 (-C), IVSI.5 (G > C), codon 5 (-CT), codon 8/9 (+G), IVSII.745 (C > G), codon 22 (7bp del), -101(C > T), codon 36/37 (-T), IVSI.15 (T > G), codon 6 (-A), -88 (G > A) were detected.

Considering the high incidence of mutations that we have found, β-thalassemia and hemoglobinopathies still seem to be a public health problem in Adana.