Abstract

Haemoglobin (Hb) abnormalities are inherited disorders in the globin chains when the haem group is in the normal state. They are mostly autosomal recessive abnormalities and common worldwide, particularly within the malarial regions of Africa. This study aimed to identify abnormal Hb stratified tribe by tribe within a cohort of Sudanese patients attending the Khartoum Teaching Hospital between March and July 2005. Initially, cellulose acetate electrophoresis (CAE) and full blood count (FBC) were used to determine the Hb type. Cation-exchange-high performance liquid chromatography (CE-HPLC) was subsequently used to evaluate results. The following range was found: HbAA (93.1%), HbAS (5.1%), HbSS (1.0%), HbAC (0.6%) and HbCC (0.2%). Thus the S gene was the most common variant found (6.1%), and it was most prevalent in the western tribes of Sudan (12.5%). Other notable findings included three patients out of HbAA subjects (0.5%) with an increased Hb F. Results from CAE were validated with CE-HPLC and findings were identical. Additional quantitative data is available with CE-HPLC, but it is expensive in terms of operation and maintenance. CAE therefore remains the technique of choice in developing countries. CAE is recommended as a suitable technique for clinical use in the developing world. Rates of genetic disorder can be reduced with improved health management and further research is also recommended into the presence of Hb F, hereditary persistence of foetal Hb (HPFH) and δβ-thalassaemia in HbAA.

Key words: Haemoglobin disorders, sickle cell anaeamia, cation-exchange-high performance liquid chromatography (CE-HPLC), electrophoresis.

Abbreviation

Hb, Haemoglobin; CAE, cellulose acetate electrophoresis; FBC, full blood count; CE-HPLC, cation-exchange-high performance liquid chromatography; SCA, sickle cell anaemia; EDTA, ethylenediaminetetraacetic acid; RTM, retention time marker; RFLP,restriction fragment length polymorphism; RBC, red blood cells.