Objective: To determine accurately the relative frequencies and enzyme activities of the polymorphic variants of G6PD in a homogeneous population in Nigeria.
Setting: Abanla village in the outskirt of Ibadan city and the University College Hospital, Ibadan Nigeria.
Subject: Seven hundred and twenty one subjects who belong to the Yoruba tribe of Southwestern Nigeria.
Method: Two mls of blood was withdrawn from each subject. G6PD activity was quantified by spectrophotometry. DNA was extracted for genotyping of G6PD by PCR.
Results: G6PD deficiency was 23.9% and 4.6% in males and females respectively. The gene frequencies of the different G6PD variants (Gd) were in accordance with expected Hardy-Weinberg equilibrium. Only GdA-1 type was found in subjects with deficient variants. G6PD activity decreased significantly with age among non-deficient individuals. The range of enzyme activities was wide and overlapping among the different G6PD variants.
Conclusion: G6PD deficiency was very high in the population. The gene frequencies were similar to previous findings. Molecular methods of typing G6PD allowed for direct and accurate genotyping of the enzyme in both males and females without having to combine several methods.