Incidence of Sickle Cell Anaemia and Thalassaemia in Central India

Haemoglobinopathies are group of diseases characterized by abnormalities both quantitative and qualitative in the synthesis of haemoglobin. Haemoglobinopathies consist of sickle cell anaemia (SCA), thalassaemia (βT) and variant haemoglobins. In India, they are responsible for the largest number of genetic disorders and hence are of great public health hazardous. In India major concerned haemoglobinopathic disorders are sickle cell anaemia and β-thalassaemia. Of the several abnormal haemoglobin molecules, four which are widely prevalent in India include: HbS, HbβT, HbE and HbD. Examination of 6463 individuals showed high incidences for haemoglobin variants, HbS and HbβT in different ethnic groups, the frequency being varies from 0% - 20% and 0% - 9% respectively. The frequency of HbS in Brahmins is 4.17%, in Kalar 5.41%, in Rajput 2.04%, in Muslims 3.73% in Maratha 2.08% in Bania 9.09% while in Teli it is 3.65%. Among the Scheduled castes and Nomadic tribal groups HbS ranges from 1% - 12%; in backward caste categories it varies from 3% - 16%; while in Scheduled tribes it ranges from 0% - 20%. The high magnitude of sickle cell trait has been noticed in the Pardhan (20.31%) followed by the Marar (16.10%), the Dhiwar (11.90%), the Gond (11.89%), the Mahar (11.81%) and the Bania (9.90%). A considerable high frequency (9.27%) of β-thalassaemia has been observed among the Sindhi population. Sporadic occurrence of HbβT and HbD among other communities suggested the gradual spread of the genes into the region. The present findings in 11 communities with the thalassaemia syndrome suggest that the β-thalassaemia is accompanied by raised level of HbA2. Unusual greater mean RBC and WBC suggest the high concentration of hypochromic microcytosis in anaemia. The mean MCV and MCH in HbβT and HbD are much lower than the normal ranges compared to HbS. The mean MCHC is much lower in HbβT, HbDD and HbS than the normal range. The cumulative gene frequency of haemoglobinopathies in India is 4.2%. With a population of over 1 billion and a birth rate of 28 per 1000, there are over 42 million carriers and over 12,000 infants are born each year with a major and clinical significant haemoglobinopathy. Out of these, clinically significant sickle cell anaemia and β-thalassaemic disorders account for almost equal numbers.