Prenatal Diagnosis of Sickle Cell Anemia and β-Thalassemia in Southern Turkey

Abstract

Hemoglobinopathies are the most common genetic diseases in Turkey. The incidence of sickle cell trait is 10.0% and β-thalassemia (β-thal) trait is 3.7% in the Çukurova region of southern Turkey. Sickle cell anemia is prevalent in the Çukurova region, but β-thal is seen all over the country. A prenatal diagnosis center was established in 1992 at Adana, Turkey, for the prevention of sickle cell anemia and β-thal. Fifteen hundred and seventy-five fetuses were examined at the Çukurova University Hospital, Adana, Turkey. Three hundred and eighty-six fetuses were diagnosed as homozygous or compound heterozygous for sickle cell anemia and β-thal. A total of 15 different β-thal mutations were characterized in the parents. The incidence of the IVS-I-110 (G > A) mutation accounted for about 50.0% of the parents with β-thal trait. Twenty-four different genotypes were observed in this study. A total of 286 fetuses were diagnosed with homozygous sickle cell disease, 57 fetuses were β-thal homozygotes, 25 fetuses were compound heterozygotes with Hb S [β6(A3)Glu→Val, GAG > GTG], and 18 of the fetuses were double heterozygotes for β-thal mutations.

Keywords:

• Sickle cell anemia
• β-Thalassemia (β-thal)
• Prenatal diagnosis
• Hemoglobin (Hb) variants