Inherited hemoglobin disorders like alpha thalassemia and sickle gene are common in the Indian subcontinent. These disorders in the heterozygous state act as malaria resistance genes and influence the susceptibility to Plasmodium falciparum malaria. There is inadequate knowledge about the epidemiology of these malaria resistance genes in the tribal dominated malaria endemic region of the state of Odisha in eastern India. A cross sectional prevalence study was undertaken in 594 subjects in five tribal populations in this region, namely, Sahara (42.4%), Kutia Kandha (30.0%), Kuda (15.8%), Gond (9.8%), and Oraon (2.0%). Sickling test, Hb electrophoresis, HPLC, and molecular studies were undertaken to diagnose the prevalence of sickle allele, β-thalassemia allele, and deletional alpha thalassemia. Sickle and β thalassemia alleles were found in 13.1% and 3.4% of subjects, respectively. Sickle allele was found both in heterozygous (10.1%) and homozygous state (3.03%). The prevalence of alpha thalassemia was 50.84% with an allelic frequency of 0.37. Both α？3.7 and α？4.2 alpha thalassemia were detected with an allele frequency of 0.33 and 0.04, respectively. The high prevalence of alpha thalassemia and sickle gene in this population is probably due to selection pressure of endemic malaria in this part of India. 1. Introduction Inherited hemoglobin disorders are the commonest monogenic diseases in humans [1]. Between 3,00,000 and 4,00,000 babies are born each year with serious hemoglobin disorders and up to 90% of these births occur in low and middle income countries [2]. Many of these inherited hemoglobin disorders are malaria resistance genes and in the heterozygous state influence the susceptibility to P. falciparum malaria [3, 4]. However our knowledge regarding their epidemiology and the pathophysiological basis of malaria protection is inadequate [3]. Alpha thalassemia, a commonly encountered inherited hemoglobin disorder presents in one of four clinical phenotypes (a) clinically asymptomatic (occurring in silent carrier state) due to a single alpha gene deletion (– / ) with no or little hematological changes [5], (b) alpha thalassemia minor due to deletion of two genes (– /– ; –？–/ ), (c) hemoglobin H disease due to deletion of three of the four alpha genes (–？–/– ), and (d) Barts hydrops fetalis, a fatal hemoglobin produced due to deletion of all four alpha genes (–？–/–？–) [5]. Both alpha thalassemia minor and hemoglobin H lead to a phenotype resembling thalassemia intermedia [4]. Alpha thalassemia is especially frequent in Mediterranean countries, South
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