Frequency of foetal haemoglobin and haemoglobin values in various haemoglobin genotypes in Calabar, Nigeria.

The frequency of foetal haemoglobin (HbF) and haemoglobin (Hb) levels were determined among 108 subjects with different haemoglobin genotypes in Calabar, between March and October, 1996. Hb-genotype was determined using the cellulose acetate method, while HbF and Hb were estimated using the modified Betke alkaline denaturation method and cyanmethaemoglobin techniques respectively. Haemoglobin genotype SS individuals had the highest mean HbF concentration of (3.05 +/- 1.61) as compared to AA and AS subjects with means of 0.195 +/- 0.25 and 1.072 +/- 0.98 respectively. This relationship was statistically significant (P < 0.02). On the other hand, AA subjects had the highest mean haemoglobin concentration (12.79 +/- 1.19) while SS subjects had the lowest (10.65 +/- 2.06). This study has indicated the persistence of HbF into adult life in this locality. Since HbF is associated with natural anti-sickling properties, its role as a monitoring factor in the management of sickle cell anaemia is examined in detail.