Cross Sectional Analysis indicates that alpha thalassemia deletion mutation is prevalent in a South Indian Population

Abstract

Thalassemia is a group of genetic disorders characterized by quantitative defects in globin chain synthesis. Deletions of either one (α -thalassemia 2) or both (α -thalassaemia 1) α-globin genes on chromosome 16 account for over 95% of alpha thalassemia cases. The subsequent absence or decrease of hemoglobin production results in microcytosis with varying degrees of anemia. The present study was undertaken to investigate the prevalence of α thalassemia in a South Indian population, Nadars, inhabiting Tamil Nadu and to compare them with Asian Populations. 31 random samples were collected and genotyped using Gap PCR. Statistical analysis was done using Excel, ARLEQUIN, MEGA and GRAPH PAD. The study population Nadars has a frequency 32% of αα/-α3.7. The two-tailed p value for Fisher’s exact equals 0.0033, highly statistically significant. The dendrogram shows that Nadars clubbed with Malay population that showed a double mutation for -4.2. This means that the mutation rate for α thalassemia in both populations is significant and Nadars need to be studied in depth for the -4.2 mutation. The principal component analysis pointed out Nadars is perhaps unique because of αα/-α3.7 genotype and the need of the hour is to screen all south Indian populations for thalassemia mutations in general and alpha thalassemia in particular.