Prenatal Molecular Diagnosis of β-Thalassemia and Sickle Cell Anemia in the Syrian Population

Our objective was to evaluate the prenatal diagnosis (PND) of beta-thalassemia (beta-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 beta-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 [beta 6(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 beta-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 beta-thal major (beta-TM).