Genetic variants in myostatin and its receptors promote elite athlete status.

BACKGROUND: While product of the myostatin gene (MSTN) is an important factor influencing muscle growth, which is well confirmed in nonhuman species, it has not been clearly confirmed whether MSTN expression influences interindividual differences in skeletal muscle mass, affects posttraining changes, or plays a role in the age-related loss of muscle mass and function in humans. Although the inconclusive results are usually explained by ethnic differences and the low frequency of some alleles, it is possible that the role of receptors (ACVR2A and ACVR2B) that affect the biological activity of myostatin is crucial. Therefore, we investigated the sequences of the MSTN, ACVR2A, and ACVR2B genes and determined the interaction between allelic variants and athletic performance and competition level in the Caucasian population. One hundred-two athletes were recruited for the sequencing study, and whole-genome sequencing (WGS) was performed. Second, 330 athletes and 365 controls were included, and real-time PCR was performed. RESULTS: The sequence analysis revealed two polymorphisms relatively common in the athlete cohort, and the alternate allele showed overrepresentation in athletes: MSTN rs11333758 and ACVR2A rs3764955. Regarding the polymorphic site MSTN rs11333758, there was a significant overrepresentation of the -/- genotype in all high-elite and mixed-sport high-elite athletes. Carriers of the ACVR2A rs3764955 CC and GG genotypes were more likely to be elite and high-elite athletes. In addition, carriers of the CC genotype were more likely to be in the mixed-sport subelite group. The gene‒gene interaction analysis revealed that mixed-sport high elite athletes showed significant underrepresentation of the ACVR2A rs3764955 GC - MSTN rs11333758 AA genotype combination. In the same group, we observed a significant overrepresentation of the ACVR2A rs3764955 GC - MSTN rs11333758 -/- and the ACVR2A rs3764955 CC - MSTN rs11333758 -/- genotype combinations. CONCLUSIONS: We showed that the specific genotypes of the MSTN rs11333758 and ACVR2A rs3764955, either individually or in gene‒gene combination, are significantly associated with athletes' competition level in the Polish population, especially in the mixed-sports athlete group. Thus, although further research is required, these polymorphisms, alone or in combination with other polymorphisms, are among the numerous candidates that could explain individual variations in muscle phenotypes.