Sickle cell disease in Africa: an urgent need for longitudinal cohort studies

Sickle cell disease is caused by a single point mutation (Glu6Val) that promotes polymerisation of haemoglobin S and sickling of erythrocytes. Inflammation, haemolysis, microvascular obstruction, and organ damage characterise the clinical expression of the disease. Environmental and genetic factors influence many pathophysiological aspects of sickle cell disease. It is estimated that 305 800 babies are born each year with the disease worldwide, with nearly 75% of these births in sub-Saharan Africa.