Abstract
Using a prospective and retrospective approach, the features of sickle cell disease (SCD) were investigated in 137 SCD children from the south-western region of Saudi Arabia. The patients were followed for a period of 2-5 years, during which period the severity of the disease was assessed and a 'severity index', was calculated for individual patients. The patients with SCD were classified into five groups based on the absence of thalassaemia (sickle cell anaemia, SCA), presence of beta zero-thalassaemia (HbS/beta zero-thalassaemia), SCA with alpha-thalassaemia.2 [heterozygotes (-alpha/alpha alpha) or homozygotes (-alpha/alpha)] and S/beta zero-thalassaemia with alpha-thalassaemia. The results showed a high prevalence of associated alpha-thalassaemia and variable levels of HbF in these patients. SCA patients with associated alpha-thalassaemia (-alpha/-alpha) and S/beta zero-thalassaemia patients with one alpha-gene deletion had the highest values for haematological parameters and lowest values of red cell indices. No specific difference could be identified in the clinical manifestations in the different groups with the exception that long bone crisis and hand-foot syndrome were not encountered in patients with associated alpha-thalassaemia. The frequency of hepatomegaly and splenomegaly was also lower in this group.