Sickle Cell Disease in Central India: High Prevalence of Sickle/Beta Thalassemia and Severe Dsiease Phenotype

Abstract

Objectives: To assess the clinical, haematological and molecular features of sickle cell disease in central India where the disease has been reported to be more severe than the mild clinical course usually observed in the Asian haplotype of homozygous sickle cell (SS) disease.Methods: A cross-sectional assessment of 91 consecutive patients with sickle cell disease attending clinics at the Akola Government Medical College, Akola, Maharastra State, India.Results: Of the 91 patients, who were predominantly of the scheduled caste community, 49 had SS disease, 6 had sickle cell-HbD Punjab, and 36 had sickle cell-beta thalassaemia. Of the patients with sickle cell-beta thalassaemia, the beta thalassemia mutation was IVS1-5 G>C mutation in 25 patients (69%) while the rest had one of seven other molecular mutations identified (Table1). Contrary to commonly held beliefs, alpha thalassaemia occurred in only 9/90 (10%) of subjects but fetal haemoglobin (HbF) levels were markedly elevated with mean and median levels of 24.4%. All except 3 SS disease patients had the Xmn1(+/+) polymorphism. These patients exhibited many of the severe manifestations of sickle cell disease. Comparison of SS disease and sickle cell-beta thalassaemia showed no differences in the prevalence of dactylitis, bone pain crisis, acute chest syndrome, haemoglobin level, reticulocyte counts or hydroxyurea usage but patients with sickle cell-beta thalassaemia had significantly more hospital admissions, blood transfusions, and greater frequencies of splenomegaly and hepatomegaly.Conclusions: Many of the patients with sickle cell disease in central India appear to have relatively severe manifestations. This appears to be due to much lower frequencies of alpha thalassaemia and more frequent sickle cell-beta thalassaemia. There is a need for assessment of the indications and policies for blood transfusion and for hydroxyurea.Table 1Beta Thalassemia mutations associated with HbS/Beta Thalassemia in AkolaMutationExpressionNumberIVS 1-5 (G>C)severe b+22IVS 1-1 (G>A)bo3Cd 15 (-T)bo2Cd 30 (G>C)bo2Cd 15 (G>A)bo1Cd 39 (C>T)bo1Cd 41/42 (-CTTT)bo1619 bp deletionbo1Total 36 DisclosuresNo relevant conflicts of interest to declare.