Prevalence of ACTN3 (the athlete gene) R577X polymorphism in Iranian population

Ability of athletes in speed or endurance contests somehow is determined by inherited muscle fiber types. One of the important genes involved in sport genetics is ACTN3 that is located on chromosome 11q13-q14 and encodes α-actinin-3, which belongs to highly conserved family of α-actinin proteins. Genetic analysis of α-actinin-3 gene has showed a polymorphism R577X (rs1815739), which results in premature stop codon and leads to non functional α-actnin-3 protein. ACTN3 genotype can contribute to the performance in elite and endurance activities. R577X polymorphism replaces arginine by stop codon. Individuals homozygous for R577 have full copy of α-actinin-3 and elite and power sprint athletes show significantly higher frequency of 577R allele. In the other hand, some studies represented that X allele have high level of frequency in endurance athletes. However, this data remains controversial Since there is no information about the frequency of ACTN3 genotype in our population therefore as the first step it is essential to determine the genetic background of Iranian population. The objective of this study was to genotype normal Iranian individuals to determine the prevalence of each allele in our population.

We used PCR-RFLP method for genotyping 210 normal individuals.

Total of 210 Iranian normal individuals for distribution of R577X and R alleles were genotyped. The different genotypes were as follow; 24% RR (50/210), 65%RX (136/210) and 11%XX (24/210), with allelic distribution of 0.56 and 0.44 for 577R and 577X alleles of ACTN3.

This allelic distribution for Iranian's is more close to Caucasian population, which is concurrent with the route of ancient human's migration from Iran Plateau toward Europe. Our results showed no different patterns of allelic distribution among female and males, which was the same in other studies too, although some differences has been reported in the studies on athletes population.