Frequency of the IGF A/G rs7136446 polymorphism and athletic performance
Previous studies have shown that carrying the minor T allele of the IGF C-1245T polymorphism was associated with higher circulating IGF-I levels, greater muscle mass and improved power athletic performance. The aim of the present study was to assess the frequency distribution of another IGF-I single nucleotide polymorphism (SNP), the A/G rs7136446, among Israeli athletes. The IGF A/G rs7136446 polymorphism was determined in 185 short (n=72) and long-distance (n=113) runners, 94 short (n=44) and long-distance (n=50) swimmers, 54 weight-lifters and 111 controls. There were no significant differences in GG carriers, previously described as associated with higher maximal force production, between the athletes and controls. The only statistical significant difference in GG carriers was found between the sprinters (24%) and weight-lifters (9%; p<0.05). Although a single polymorphism cannot determine an athlete’s ability to succeed or fail in sports, the present findings suggest a potential importance of IGF-I polymorphisms mainly to power sports and in particular to speed sport performance.