Association of the ACTN3 R577X (rs1815739) polymorphism with elite power sports: A meta-analysis
Tharabenjasin P, Pabalan N, Jarjanazi H
Evidence is still building up
Summary
A meta-analysis pooling 44 studies (~20,000 people: 4,850 elite power athletes and 15,903 controls). The R allele of ACTN3 — which encodes alpha-actinin-3, a protein in fast-twitch muscle fibers — was somewhat more common in elite power athletes (R allele odds ratio ≈1.20 [1.12–1.30]), and more clearly so in women (OR 1.58). The effect size is small, however, and elite athletes exist across every genotype. Genetics is only part of the predisposition to power and sprint performance, not a sole determinant of talent.
Key findings
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The R allele is somewhat more common in elite power athletes (OR ≈1.20), and more clearly so in women (OR 1.58)
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The R allele relates to production of alpha-actinin-3, a protein in fast-twitch muscle fibers
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The effect size is small and elite athletes exist across all genotypes (only part of the predisposition)
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Limitations: between-study heterogeneity, poor control matching, and over-representation of Western populations
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