Epidemiological Study of Glucose-6-phosphate Dehydrogenase Deficiency in Scheduled Caste Population of India

The aim of the present study was to determine the glucose-6-phostphate dehydrogenase (G6PD) deficiency in scheduled caste (SC) population of eastern Uttar Pradesh, India. After taking clearance certificate from the Institutional Ethics Committee, blood samples were collected from total 200 healthy individuals belonging to scheduled caste. G6PD deficiency analysis was done by methemoglobin test according to the method of Brewer et al. (1962). Out of 200 samples, 20 individuals were glucose-6-phosphate dehydrogenase deficient and 22 samples were heterozygous that is, carriers. The percentage of G6PD deficient (Gd+/+) and G6PD carrier (Gd+/Gd？) phenotypes were 10% and 11%, respectively. The frequency of mutant allele (Gd？) was observed 0.172. Early detection and prevention is the key strategy for successful management and control of this genetic disease. 1. Introduction Glucose-6-phosphate dehydrogenase (G6PD) is a highly conserved housekeeping enzyme and rate-limiting enzyme of the pentose phosphate pathway in all cells [1]. The pentose phosphate pathway (PPP) converts glucose to ribose-5-phosphate, a precursor to RNA, DNA, ATP, CoA, NAD, and FAD. In addition, in mammalian cells G6PD provides reductive potential in the form of NADPH [2]. G6PD is a ubiquitous enzyme that must be quite ancient in evolution because it has been found in all organisms, from prokaryotes to yeasts, to protozoa, to plants, and animals [3, 4]. G6PD deficiency results from mutations in the G6PD gene and is well-known common cause of hemolytic anemia in human [5]. Most cells have a back-up system of other metabolic pathways that can generate the intracellular NADPH necessary, but red blood cells do not have the other NADPH producers. Therefore, G6PD deficiency becomes especially lethal in red blood cells, where any oxidative stress will result in hemolytic anemia. G6PD deficiency was first identified in American blacks in the course of studies of sensitivity to the hemolytic effect of primaquine [6]. Clinically, this deficiency affects as many as 400 million individuals worldwide [3] and predisposes affected individuals to neonatal jaundice, drug- or infection-mediated hemolytic crisis, favism, and, less commonly, to chronic nonspherocytic hemolytic anemia [7]. The G6PD gene is present on the long arm of the X chromosome (Xq28) and consists of 13 exons with a length of 18？kb [8]. The active form of G6PD enzyme is either a dimer or a tetramer of a single polypeptide subunit of about 59？kD [9]. G6PD deficiency is mainly found in populations originating from tropical and subtropical