Distribution of sickle cell disease in Africa

Abstract

The term sickle cell disease includes a variety of pathological conditions resulting from the inheritance of sickle haemoglobin either in a homozygous state or the S gene in a heterozygous state with another abnormal haemoglobin e.g SS, SC, SD, S B_thal, SOArab, SD, SG. The origin of the haemoglobin S (HbS) gene has been rather controversial. The HbS gene has often been regarded as an African ancestry because of its high frequency among blacks. Sickle cell anaemia is also prevalent in parts of Asia mainly the Arabian peninsula and the Indian subcontinent. It is seen in parts of Europe (mainly Greece and Sicily). It is also prevalent where people from the above areas have migrated. It is now prevalent in America including tropical America. It has recently been recognised in Southern Nepal. The S gene exists in all the three major "races" of human kind:- black, white and oriental.