Analysis of beta globin mutations in the Indian population: presence of rare and novel mutations and region-wise heterogeneity.
ABSTRACT Beta thalassaemia is a major public health problem in India. A comprehensive database of the spectrum of mutations causing beta thalassaemia in the Indian population is necessary. This study in which a large number of patients with beta thalassaemia including those from certain regions that were not explored earlier shows a great heterogeneity of mutations. Several novel and rare alleles that have not been reported earlier in the Indian population have been identified, and mutations differ in frequency in different regions of the country. This information on the spectrum of mutations has implications for the control of beta thalassaemia in a population with complex ethnic background and also on the genotype-phenotype correlation of the disease.
Article: Genetic Heterogeneity of Beta Globin Mutations among Asian-Indians and Importance in Genetic Counselling and Diagnosis.[show abstract] [hide abstract]
ABSTRACT: There are an estimated 45 million carriers of β-thalassemia trait and about 12,000-15,000 infants with β-thalassemia major are born every year in India. Thalassemia major constitutes a significant burden on the health care system. The burden of thalassemia major can be decreased by premarital screening and prenatal diagnosis. The success of prenatal diagnosis requires proper knowledge of spectrum of β-thalassemia mutations. In present study, β-thalassemia mutations were characterized in 300 thalassemia cases from 2007 to 2010 using ARMS-PCR and DNA sequencing. The five most common mutations accounted 78.9% of the studied chromosomes that includes IVS1-5(G>C), Cod 41-42(-TCTT), Cod8-9(+G), Cod16(-C) and 619bp del. Though IVS1-5(G>C) is most common mutation in all the communities, the percentage prevalence were calculated on sub caste basis and found that IVS1-5(G>C) percentage prevalence varied from 25 to 60 in Aroras & Khatris and Thakur respectively. Interestingly Cod41-42(-TCTT) mutation which is the second commonest among the mutations reported was totally absent in Kayasthas and Muslim community. These findings have implications for providing molecular diagnosis, genetic counseling and prenatal diagnosis to high risk couples of β-thalassemia.Mediterranean Journal of Hematology and Infectious Diseases 01/2013; 5(1):e2013003.
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ABSTRACT: The first case of thalassaemia, described in a non-Mediterranean person, was from India. Subsequently, cases of thalassaemia were documented in all parts of India. Centres for care of thalassaemics were started in the mid-1970s in Mumbai and Delhi, and then in other cities. The parent's associations, with the help of International Thalassemia Federation, greatly helped in improving the care of thalassaemics. Obtaining blood for transfusion was difficult, but the Indian Red Cross Society and the parent's associations played a crucial role in arranging voluntary donations of blood. Chelation with deferoxamine was used sparingly due to the high cost. The Indian physicians conducted trials with deferiprone, and the drug was first approved and marketed in India. Deferasirox is also now being administered. Studies of physical and pubertal growth documented significant retardation, suggesting that generally patients receive inadequate chelation and transfusions. Bone marrow transplantation is available at a number of centres, and cord blood stem cell storage facilities have been established. Information about mutations in different parts of India is available, and ThalInd, an Indian database has been set up. There is a need to set up preimplantation genetic diagnosis and non-invasive prenatal diagnosis. It is argued that too much emphasis should not be placed on premarital screening. The focus should be on screening pregnant women to yield immediate results in reducing the burden of this disorder. Care of thalassaemia has been included in the 12 th 5-year Plan of the Government of India. Many States now provide blood transfusions and chelation free of cost. Although inadequacies in care of thalassaemia remain, but the outlook is bright, and the stage is set for initiating a control programme in the high risk States.The Indian journal of medical research 10/2011; 134:507-21. · 1.84 Impact Factor
Article: Invasive & non-invasive approaches for prenatal diagnosis of haemoglobinopathies: experiences from India.[show abstract] [hide abstract]
ABSTRACT: The thalassaemias and sickle cell disease are the commonest monogenic disorders in India. There are an estimated 7500 - 12,000 babies with β-thalassaemia major born every year in the country. While the overall prevalence of carriers in different States varies from 1.5 to 4 per cent, recent work has shown considerable variations in frequencies even within States. Thus, micromapping would help to determine the true burden of the disease. Although screening in antenatal clinics is being done at many centres, only 15-20 per cent of pregnant women register in antenatal clinics in public hospitals in the first trimester of pregnancy. There are only a handful of centres in major cities in this vast country where prenatal diagnosis is done. There is considerable molecular heterogeneity with 64 mutations identified, of which 6 to 7 common mutations account for 80-90 per cent of mutant alleles. First trimester foetal diagnosis is done by chorionic villus sampling (CVS) and DNA analysis using reverse dot blot hybridization, amplification refractory mutation system (ARMS) and DNA sequencing. Second trimester diagnosis is done by cordocentesis and foetal blood analysis on HPLC at a few centres. Our experience on prenatal diagnosis of haemoglobinopathies in 2221 pregnancies has shown that >90 per cent of couples were referred for prenatal diagnosis of β-thalassaemia after having one or more affected children while about 35 per cent of couples were referred for prenatal diagnosis of sickle cell disorders prospectively. There is a clear need for more data from India on non-invasive approaches for prenatal diagnosis.The Indian journal of medical research 10/2011; 134:552-60. · 1.84 Impact Factor