Indian Pediatrics 2001; 38: 530-534
Pattern of Hemoglobinopathies in Western Maharashtra
Hemoglobinopathies are a group of genetic disorders of hemoglobin. These form a major group with an estimate of 250 ΄ 106 individuals with this condition (4.5% of the total world population) throughout the world(1). The frequency of beta thalassemia in India ranges from 3.5 to 15% in general population. Every year 10,000 children with thalassemia major are born in India, which constitutes 10% of the total number in the world(2). Amongst the structural hemoglobin variants HbS, HbD and HbE, 25% traits are of sickle cell disease(3). The overall alpha gene deletion frequency is 0.05 to 0.98%(4). In order to know the pattern of hemoglobinopathies in population of Western Maharashtra, the following study was carried out.
Sassoon General Hospital is one of the biggest government hospital in Western Maharashtra. The Genetics Department of this hospital is the only institute in Pune, which undertakes research on thalassemia and hemo-globinopathies. The diagnosis and treatment of thalassemia is provided free of cost here. We have a Thalassemia Unit of the Department of Pediatrics, which provides blood transfusion free of cost to the patients, who are admitted daily. For these reasons the number of patients visiting this hospital for diagnosis and treatment is so high that it could be considered representative of the entire Western Maharashtra region.
Subjects studied were the patients and their families referred to the Genetic Clinic of Sassoon General Hospital, Pune for the diagnosis of hemoglobinopathies. A total of 1291 subjects were studied. These included 891 cases from the pediatric age group and 400 cases from the adult age group. Of the total 891 cases from pediatric age group, 273 (21.1%) cases were from 0-2 yr age group, 381 (29.5%) cases were from 2-5 yr age group and 237 (18.45%) were from 5-10 yr age group. From the pediatric age group, 591 (66.38%) males and 300 (33.77%) females were studied. From the adult age group, 209 (52.35%) males and 191 (47.85%) females were studied. Two ml blood was collected in the Wintrobes bulb, hemolysates were prepared and subjected to hemoglobin electrophoresis at alkaline pH using Cellulose Acetate membrance(5). NESTROFT (Naked Eye Single Tube Red Cell Osmotic Fragility Test) was done for carrier detection of thalassemia(6-8). Finally, in order to confirm and quantitate abnormal hemoglobins, the samples were subjected to Bio-Rad Variant machine. Beta thalassemia short program was run for this purpose(9-11).
The criteria used for the diagnosis of beta thalassemia trait were positive family history, hemoglobin level below 10.0 g/dl (considering both the sexes and adult age group), NESTROFT positivity and HbA2 level more than 3.0% as estimated on the Bio-Rad Variant. The criteria used for the diagnosis of beta thalassemia major were positive family history, hemoglobin level below 5.0 g/dl (considering both sexes and pediatric age group), presence of characteristic, thalassemia facies, hepatosplenomegaly. Peripheral blood smear showing severe hypochromia, micro-cytosis ++, anisopoikilocytosis ++, polychro-masia ++, teardrop cells, target cells +, MCV below 60 fl, MCH below 20 pg, hemoglobin electrophoresis at alkaline pH showing A+F pattern and level of HbF above 10% by Singers alkali denaturation method.
Table I__Observed frequency of various disorders
Pediatric age group: Amongst the total 891 subjects studied, 790 (88.66%) were detected to be normal, 101 (11.3%) showed the pre-sence of one or the other hemoglobino-pathy. Thalassemia major was detected in 76 (8.5%) subjects, beta thalassemia trait in 4 (0.5%), sickle cell disease in 16 (1.8%) HbE in 4 (0.5%) and HbD disease in 1 (0.1%) (Table I).
Adult age group: Amongst the total 400 subjects studied, 294 (73.5%) were normal, 106 (26.5%) showed the presence of one or the other hemoglobin disorder. Beta thalassemia trait was detected in 87 (21.8%) subjects, sickle cell disease in 14 (3.5%), HbE in 4 (1.0%) and HbD disease in 1 (0.25%) subject. (Table I).
The communities which showed higher incidence of beta thalassemia were Navbudha, Maratha and Muslim. Amongst the total (n = 167) cases of beta thalassemia studied, 56 (33.5%) were from Navbudha community, followed by Maratha 51(30.5%), Muslim 22 (13.2%), Brahmin 8 (4.8%), Gujarati 6 (3.6%), Dhangar 5 (3.0%), Koli and Patil 3 each (1.8%), Pardeshi, Banjara, Gargi, Sindhi and Lingayat 2 (1.2%) each, and Ramoshi Kunbi and Mang 1 (0.6%) each. The communities which showed higher frequency of sickle cell anemia were Navbudha, Madari and Maratha. Amongst the total (n = 30) cases of sickle cell anemia studied 21 (70%) were from Navbudha community followed by Madari 4 (13.3%), Pawra and Maratha 2 (6.7%) each and Koshti-1(3.3%). A higher frequency of HbE disease was found in Muslim community. Of the total (n = 8) cases of HbE disease studied 6 (75%) were from Muslim, 1 (12.5%) from Navbudha and 1 (12.5%) from Bengali communities. Both the cases of HbD were from Maratha community.
Table II__ Frequency of Hemoglobinopathies and Thalassemia in Various States of India with that of Western Maharashtra(2,12,13)
N = Total number of cases studied; n = Number
of cases of a particular disease studied;
Amongst the hemoglobin disorders beta thalassemia, sickle cell disease, HbE disease are HbD disease are prevalent in Western Maharashtra. Beta thalassemia is the most prevalent disorder with an overall frequency of 7.0% (considering both adult and pediatric age groups). The comparative frequency of beta thalassemia in western Maharashtra amongst the other hemoglobinopathies is 81.1% (167 cases). The communities which showed the higher incidence of these disorders were Navbudha, Maratha and Muslim.
The distribution of beta thalassemia gene is not uniform in the Indian subcontinent. The highest frequency of beta thalassemia trait is reported in Gujarat, followed by Sindh, Punjab, Tamil Nadu, South India and Maharashtra (1.9%) as shown in Table II(2,12). The frequency of beta thalassemia trait in Western Maharashtra reported by us (7.0%) is in between that of Punjab and Tamil Nadu.
The highest frequency of sickle cell gene is reported in Orissa followed by Assam, Madhya Pradesh, Uttar Pradesh, Tamil Nadu and Gujarat. The incidence of the sickle cell disease reported by us (2.3%) is in between that of Gujarat and Rajasthan. It agrees well with the frequency reported for Maha-rashtra(2.5%)(12).
HbE disease is most frequently found in Eastern and far Eastern parts of India (average frequency 10.9%)(12). It is sporadically found in many parts of the country. The highest frequency is recorded in Assam followed by Meghalaya, Arunachal Pradesh, West Bengal, Manipur, Nagaland and Sikkim. The fre-quency reported by us in Western Maharashtra (0.6%) is similar to the lowest frequency found in Eastern parts (0.7%)
The frequency of HbD is as a whole lower in India. The average prevalence is 1%(12). The highest frequency is recorded in Punjab followed by Jammu and Kashmir, Karnataka, Gujarat, Orissa, Rajasthan and Madhya Pradesh. The reported frequency in Maha-rashtra is 0.6%(12).
Contributors: SSA co-ordinated the study, collected the data and drafted the manuscript, she will act as the guarantor for the article. MAP helped in design and interpretation of the data. VV helped in analysis and interpretation of the clinical data. GDM and DGB participated in technical part of the study and in data collection. VAK and MPB participated in drafting the paper and also in technical part.
Funding: Department of Biotechnology, New Delhi and Council of Scientific and Industrial Research, NPL campus, Dr. Krishnan Marg, New Delhi, 110 012.
Competing interests: None stated.