ACTN3 genotyping by real-time PCR in the Italian population and athletes

Purpose: Development of two novel sets of primers and probes to detect R577X and Q523R polymorphisms of the alpha-actinin-3 (ACTN3) gene by real-time PCR. We report the allelic frequencies observed in Italian individuals from the general population and athletes. Athletic performance is influenced by training, environmental factors, and genetic predisposition. Actn3 belongs to a family of actin-binding proteins and is supposed to influence sport performance. Methods: Primer-probe set design and protocol optimization for real-time PCR genotyping of R577X and Q523R polymorphisms. The assay was verified using a traditional PCR-RFLP approach and applied on an Italian population sample (102 male subjects and 42 athletes). Results: Haplotype distribution confirmed the presence of linkage disequilibrium between the polymorphisms, both in the Italian general population and athletes (respectively: chi=54.4, P <= 0.001 and chi=24.5, P <= 0.001). Within the general population, a large percentage of homozygous subjects (21.6%) was deficient for Actn3. No significant differences were observed in athletes. The concordance between PCR-RFLP and real-time PCR results was 100 and 93% for polymorphisms Q523R and R577X, respectively. Conclusion: Real-time PCR represents an effective approach for typing ACTN3 alleles. Allelic frequencies in the Italian population are consistent with those seen in other studies on Caucasians.