Genetic variability at the D1S80 minisatellite: predominance of allele 18 among some Indian populations

Abstract

Background: Hypervariable minisatellites are considered as useful genetic markers in population studies because they are highly polymorphic, multiallelic and co-dominant in nature. The D1S80 minisatellite is one of the well studied markers, and has been used for differentiating population groups of various geographic, linguistic, cultural and genetic origins.Objective: The present study reports the genetic variation observed at the D1S80 minisatellite among seven anthropologically distinct ethnic groups from Kerala state in south India and is compared with other reported Indian and world populations.Subjects and methods: DNA was isolated from the peripheral blood samples of 282 random, normal and healthy volunteers, PCR amplified and electrophoresed on 4% PAGE followed by silver staining.Results: A total of 22 alleles (14–39 repeats) were detected with high heterozygosity (0.63–0.84) and Polymorphic Information Content (PIC) values (0.63–0.83). Allele 18 was the predominant allele, except in Ezhavas. The comparison of allele frequency data with world populations including other studied Indian ethnic groups has revealed that the majority of Indian populations possessed allele 18 as the predominant allele. In contrast, allele 24 was reported to be the predominant allele worldwide with a few exceptions.Conclusions: This study at the D1S80 minisatellite on seven ethnic groups will provide useful information for the Indian population genetic database. However, the most important observation was the predominance of allele 18 among the majority of Indian ethnic groups. The reason is not clear yet and thus further studies on Indian ethnic groups from different regions are necessary to find out the importance of allele 18 as the predominant allele in Indian population.