Genetic variation of polymorphic NOS STR locus in ten Indian population groups

The genotyping of 313 random individuals belonging to ten different population groups from three different states of India was performed for polymorphic pentanucleotide repeat present in the 5'-flanking region of nitric oxide synthase gene (NOS2A) to study the effect of geographical and linguistic affiliations on the genetic affinities among these groups. Likelihood ratio tests showed that all the ten populations for this locus were in Hardy Weinberg equilibrium. Eleven different alleles ranging from 7 repeat to 17 repeats and 46 different genotypes were observed. The observed and the expected heterozygosity ranged from 0.72-0.94 and 0.84-0.89, respectively. The discriminating power of this locus is > or = 0.86 and the polymorphism information content of this locus in ten population groups ranged from 0.80 to 0.85. High PIC, PD and PE value of this STR showed this marker to be informative and can be used for DNA typing and population studies. The eight populations from Kerala showed a lower GST value of 0.016 compared to the GST of ten populations (G(ST) = 0.019), thereby showing that the populations from the same state showed higher genetic proximity probably due to linguistic and geographical proximity between them.