Foetal haemoglobin levels in Nigerians with sickle cell anaemia. A revisitation

Foetal haemoglobin (HbF) levels were estimated by the alkali denaturation method in 73 Nigerians with sickle cell anaemia (SCA). Subjects were studied during their asymptomatic periods and were divided into three groups based on HbF levels. Group I: HbF levels < 10%; group II: HbF levels > or = 10% but < 15%; group III: HbF levels > or = 15%. Mean crises per year, number of organ (system) complications, degree of anaemia, as well as total severity scores derived from these three parameters did not vary significantly in the three groups. Similarly, HbF levels failed to manifest significant correlation between either frequency of crises, occurrence of complications, degree of anaemia or the derived total severity scores. It is probable that in Nigerian SCA subjects whose HbF concentrations are mostly < 20%, other variables apart from HbF may influence the severity of their disease.