ASSOCIATION BETWEEN A TETRANUCLEOTIDE (GGAA)n REPEAT IN THE ERYTHROPOIETIN RECEPTOR GENE AND ENDURANCE PERFORMANCE 296

In a case-control study, we examined the allelic frequency and genotype distribution of a tetranucleotide (GGAA)n repeat starting at -548bp in the 5′ untranslated region of the human erythropoietin receptor (EPOR) gene in elite endurance athletes (EA) and sedentary controls (SC). The EA group included 142 caucasian males recruited on the basis that they had a VO2max >73ml/kg·min-1. The SC group comprised 141 unrelated sedentary caucasian males from the Quebec Family Study. PCR technique was used to amplify the microsatellite repeat in the EPOR gene. The PCR products were separateed in a 6% denaturing polyacrylamide gel and visualized by silver staining. We observed 13 different alleles varying in size from 169bp to 217bp. In agreement with previous studies, percentage of heterozygosity in both groups was about 80%. The 193bp, 197bp and 201bp alleles were the major alleles accounting for almost 75% of all alleles. Comparing carriers vs. non-carriers of (GGAA)n repeats in both groups, a three-fold difference (p<0.01) was found between the prevalence of SC (n=5) and EA (n=17) subjects carrying the 185bp allele. In summary, we found suggestive evidence that the 185bp allele of the tetranucleotide repeat in the EPOR gene is associated with endurance performance capacity and may account for some of the differences between EA and SC status.