Distribution of performance-related gene polymorphisms (ACTN3 R577X and ACE ID) in different ethnic groups of the Indian Army

Abstract

India has a heterogeneous geographical location with varying ethnic groups with distinct genetic pools. Polymorphisms R577X and insertion/deletion (I/D), occurring in α-actinin3 (ACTN3) and angiotensin converting enzyme (ACE) genes, respectively, are reportedly associated with sprint and endurance performance. The normative genetic background of a population provides the baseline genetic diversity of the population. We investigated the distribution of R577X and I/D polymorphisms in four Indian ethnic populations employed in the Indian Army that requires high levels of physical fitness. A total of 598 army subjects with four different ethnicities were recruited for the study: Rajputs, South Indians, Gorkhas, and Ladakhis. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism followed by statistical analysis. The present study reports for the first time the genotypic distribution of ACTN3 R577X polymorphism in four ethnic groups of the Indian population with no significant change in distribution of R and X alleles among these groups and their overall percentage bearing similarity with the Caucasian population. ACE I/D polymorphism showed significant differences between Rajputs and Gorkhas, Rajputs and Ladakhis, Gorkhas and South Indians, and South Indians and Ladakhis. Combined genotypic analysis showed the highest frequencies of ID+RX in all ethnic groups. Our study reports the genetic predominance of ACE I allele in Gorkhas and I allele predominance in Ladakhis for the first time, thus suggesting that they could be better endurance performers. Both these ethnic groups evolved from the Mongolian race and hence could have similar genotypic distribution. This study provides a comparative account of the Indian normative genetic data in performance-related genes.