Perspectives in Genetics and Sickle Cell Disease Prevention in Africa: Beyond the Preliminary Data from Cameroon.

Management of sickle cell disease (SCD) in Africa needs to be accompanied by various preventive strategies, including early detection via prenatal genetic diagnosis (PND). Contrary to Cameroonian doctors who considered termination of an affected pregnancy (TAP) for SCD in 36.1%, the majority of parents (62.5%) with affected children accepted TAP in principle. In practice, most women opted for TAP (90%), justified by a huge psycho-social burden. The ethical and legal challenges of PND prompted the need to explore the use of genetics for secondary prevention of SCD. In 610 Cameroonian SCD patients, the genomic variations in two principal foetal haemoglobin-promoting loci were significantly associated with foetal haemoglobin levels. In addition, the co-inheritance of a 3.7-kb α-globin gene deletion and SCD was associated with a late disease onset and possibly improved survival: there was a much higher allele frequency of the 3.7-kb α-globin gene deletion in SCD patients (∼ 40%) than in haemoglobin AA controls (∼ 10%). The data indicate the urgent need to develop and implement policy actions in sub-Saharan Africa on at least four levels: (1) the implementation of SCD screening practices and early neonatal follow-up; (2) the development and incorporating of socio-economic support to alleviate the burden of SCD on affected families; (3) the exploration of the appropriateness of the medical abortion laws for SCD, and (4) the development of national plans for genetic medicine, including research on genomic variants that affect the phenotypes of SCD, in order to potentially use them for anticipatory guidance.