Prenatal molecular diagnosis of β-thalassemia and sickle cell anemia in the Syrian population.

Our objective was to evaluate the prenatal diagnosis (PND) of β-thalassemia (β-thal) and sickle cell anemia in Syria. Mutations detected from blood of at-risk couples and 55 amniotic fluid samples collected at the second trimester of pregnancy (14-22 weeks' gestation) were characterized. Molecular screening and direct DNA sequencing of the HBB gene was carried out. DNA analyses showed 14 affected fetuses (25.45%), 32 (58.18%) carriers and eight (14.54%) normal fetuses. It appears that 20.0% of individuals carried the sickle cell anemia mutation and 80.0% carried the β-thal mutation. Thirteen different known mutations were detected in the fetuses. The most common mutations were: IVS-II-1 (G > A), codon 39 (C > T)], IVS-I-110 (G > A), IVS-I-1 (G > A) and IVS-I-5 (G > C). The Hb S [β6(A3)Glu → Val; HBB: c.20A > T] mutation was the only abnormal hemoglobin (Hb) that was found. The results point to a successful future for PND of β-thal and sickle cell anemia in Syria, using a rapid and accurate molecular method. We hope that this method will be used as a common application approach to decrease the incidence of β-thal major (β-TM).