Two different forms of homozygous sickle-cell disease - abstract

ABSTRACT

Haematological, clinical and some molecular genetic features have been compared in two groups of patients with homozygous sickle-cell (SS) disease in Saudi Arabia, 33 patients from the Eastern Province (eastern) and 30 from the South Western Province (Western). Eastern patients all had the Asian haplotype of DNA polymorphisms within the beta globin gene cluster whereas Western patients were more variable but predominantly of the Benin haplotype. Eastern patients had significantly more deletional alpha thalassaemia, higher levels of total haemoglobin and foetal haemoglobin, and lower of HBA, mean volume reticulocytes, and platelets. Clinically, Eastern patients had a greater persistence of splenomegaly, less dactylitis, less acute chest syndrome, a more normal body build and greater subscapular skin fold thickness. Painful crises occurred with equal frequency in both groups. Avascular necrosis of the femoral head was common in both groups. The disease in the Eastern province has many mild features consistent with the higher HbF levels and more frequent alpha thalassaemia but bone pathology (painful crises, avascular necrosis of the femoral head, osteomyelitis) remains common. The disease in the West is more severe, consistent with the Benin haplotype suggesting an African origin (AU)