Prenatal diagnosis of beta-thalassaemia and sickle cell anaemia in Turkey

This paper reports our experience of molecular analysis and diagnosis of beta-thalassaemia and sickle cell anaemia (HbS) in 70 prospective parents of Turkish descent and their fetuses. Molecular screening was carried out by allele-specific oligonucleotide (ASO) hybridization of amplified DNA to the 12 most common mutations in the Turkish population. By using this approach, we were able to define the mutation in 95 per cent of chromosomes investigated. Genomic sequencing led to the additional detection of three rare mutations: Cd 44 (-C), IVS-I-5 (G-C), and IVS-I-116 (T-G). All diagnoses were successfully accomplished and no misdiagnosis occurred. Consanguineous marriage appears to contribute significantly to the frequency of affected births in Turkey. Out of the 14 homozygous fetuses, six were the result of close consanguinity. This study indicates that fetal diagnosis of beta-thalassaemia and HbS may be obtained in practically all cases, even in a heterogeneous population like the Turkish population, when early methods of fetal sampling are combined with polymerase chain reaction (PCR)-based techniques. Until gene therapy becomes a reality, the only approaches to the control of haemoglobinopathies are prevention and avoidance....Continue Reading