Table 8.
Summary of the ACTN3 R577X genotype studies with performance phenotypes
| Study | Group (sample size) | 577X allele frequency | X577X genotype frequency | Main findings |
|---|---|---|---|---|
| Yang et al. 2003 (376) | Sprint (n=73) Endurance (n=40) Controls (n=120) |
0.28 0.46 0.44 |
0.06 0.24 0.18 |
X-allele frequency lower in sprinters vs. controls & endurance |
| Niemi et al. 2005 (213) | Sprint (n=73) Endurance (n=40) Control (n=120) |
0.29 0.30 0.32 |
0.09 0.10 0.09 |
No difference in frequencies between athletes and controls |
| Lucia et al. 2006 (175) | Cyclists (n=50) Runners (n=52) Controls (n=123) |
0.49 0.46 0.45 |
0.26 0.17 0.18 |
No difference in frequencies between athletes and controls |
| Clarkson et al. 2005 (63) | Men (n=182) Women (n=287) |
0.51 0.49 |
0.264 0.268 |
Greater training-induced increase in strength in the X/X vs. R/R homozygotes in women, no difference in men. |
| Delmonico et al. 2007 (76) | Men (n=71) Women (n=86) |
0.401 0.471 |
0.211 0.279 |
In women, greater baseline strength in the X/X vs. R/R, but training-induced increase greater in the R/R vs. X/X. |
| Moran et al. 2006 (200) | Boys (n=507) Girls (n=439) |
0.42 0.41 |
0.183 0.17 |
R allele associated with faster 40 m sprint time in boys but not in girls |
| Roth et al. 2007 (274) | Strength, white (n=52) Control, white (n=668) Strength, black (n=23) Control, black (n=208) |
0.423 0.436 0.283 0.245 |
0.096 0.199 0 0.048 |
Frequency of the X/X genotype lower in athletes vs. controls; no difference in the X allele frequencies. |
| Santiago et al. 2007 (277) | Soccer (n=60) Endurance (n=102) Controls (n=123) |
0.33 0.475 0.447 |
0.15 0.215 0.178 |
X-allele frequency lower in soccer players vs. controls. |
| Papadimitriou et al. 2008 (227) | Power T&F (n=73) Endurance (n=28) Controls (n=181) |
0.342 0.375 0.461 |
0.164 0.25 0.182 |
X-allele frequency lower in power athletes vs. controls; no difference in the X/X genotype frequencies |
| McCauley et al. 2009 (190) | Young men (n=79) | 0.424 | 0.190 | No association with knee extensor muscle strength and contractile properties |
| McCauley et al. 2010 (189) | Elderly men (n=100) | 0.365 | 0.16 | No association with isometric or isokinetic knee extensor muscle function |
| Norman et al. 2009 (215) | Young men and women (n=120) | 0.454* | 0.250* | Muscle power and fatigue index derived from 30-sec Wingate test were not associated with the genotype |
| Saunders et al. 2007 (278) | Fast triathletes (n=152) Mid triathletes (n=152) Slow triathletes (n=153) Controls (n=143) |
0.41 0.42 0.45 0.47 |
0.18 0.19 0.23 0.21 |
No differences in allele and Genotype frequencies between athletes and controls |
| Scott et al. 2010 (287) | Jamaica: -Sprint athletes (n=114) -Controls, Jam (n=311) USA: -Sprint Athletes (n=113) -Controls (n=190) |
0.137 0.136 0.187 0.159 |
0.019 0.026 0.037 0.018 |
No differences in allele and genotype frequencies between athletes and controls |
| Eynon et al. 2009 (81) | Sprinters (n=81) Endurance (n=74) Controls (n=240) |
0.31 0.57 0.49 |
0.14 0.32 0.18 |
Allele and genotype frequencies significantly different in sprinters than in endurance athletes and controls#. |
| Ahmetov et al. 2010 (3) | Endurance (n=456) Controls (n=1211) |
0.332 0.390 |
0.057 0.145 |
Frequency of the X-allele and X/X genotype significantly lower in endurance athletes than in controls. |
| Druzhevskaya et al. 2008 (79) | Power athletes (n=486) Controls (n=1197) |
0.333 0.387 |
0.064 0.142 |
Frequency of the X-allele and X/X genotype significantly lower in power athletes than in controls. |
| Yang et al. 2007 (377) | Ethiopians: - endurance (n=76) - controls (n=198) Kenyans: - endurance (n=284) - controls (n=158) Nigerians: - power (n=62) - controls (n=60) |
0.309 0.342 0.132 0.085 0.064 0.083 |
0.079 0.111 0.011 0.013 0 0 |
No differences in allele and genotype frequencies between athletes and controls |
*
Subjects were selected from larger cohort to derive approximately equal number of subjects with each genotype. Therefore, 577X allele frequency is greater than in the general population.
#
Genotype frequencies in controls deviate significantly from Hardy-Weinberg Equilibrium