Inherited hemoglobin disorders in Guinea-Bissau, West Africa: a population study

The determination of the prevalence of inherited hemoglobin (Hb) disorders in endemic areas is important in order to develop programs for their control and management. The aim of this study is to determine the prevalence of inherited Hb diseases in Guinea-Bissau which is situated on the west coast of Africa, between Senegal and Guinea. One thousand and fifty-seven blood samples were collected and analyzed with high performance liquid chromatography (HPLC) for detection of beta-thalassemia (thal) and Hb variants, and by gap polymerase chain reaction (gap-PCR) for the detection of deletions in the alpha-globin genes. We found 4.7% children were heterozygous for Hb S [beta6(A3)Glu-->Val, GAG -->GTG], 0.2% were homozygous for Hb S, and 0.3% were heterozygous for Hb C [beta6(A3)Glu-->Lys, GAG -->AAG]. One child had heterozygous beta+-thal, 13.8% were heterozygous for the -alpha3.7 deletion, 1.5% were homozygous for the -alpha3.7 deletion, and 1.5% were heterozygous for the -alpha4.2 deletion. We recommend national screening programs to focus primarily on sickle cell disease, since beta-thal is rare, and the observed alpha-thal deletions are of minor genetic importance.