The 577X allele of the ACTN3 gene is associated with improved exercise capacity in women with McArdle's disease.
We assessed the possible association existing between alpha-actinin-3 (ACTN3) R577X genotypes and the capacity for performing aerobic exercise in McArdle's patients. Forty adult McArdle's disease patients and forty healthy, age and gender-matched sedentary controls (21 men, 19 women in both groups) performed a graded test until exhaustion and a constant-load test on a cycle-ergometer to determine clinically relevant indices of exercise capacity as peak oxygen uptake (VO(2peak)) and the ventilatory threshold (VT). In the group of diseased women, carriers of the X allele had a higher (P<0.01) VO(2peak) (15.0+/-1.2 ml/kg/min) and a higher (P<0.05) oxygen uptake (VO(2)) at the VT (11.2+/-1 ml/kg/min) than R/R homozygotes (VO(2peak): 9.6+/-0.5 ml/kg/min; VO(2) at the VT: 8.2+/-0.7 ml/kg/min). No differences were found in male patients. In women with McArdle's disease, ACTN3 genotypes might partly explain the large individual variability that exists in the phenotypic manifestation of this disorder.
Lucia
Alejandro
A
Universidad Europea de Madrid, Madrid, Spain. alejandro.lucia@uem.es
Gómez-Gallego
Félix
F
Santiago
Catalina
C
Pérez
Margarita
M
Maté-Muñoz
José L
JL
Chamorro-Viña
Carolina
C
Nogales-Gadea
Gisela
G
Foster
Carl
C
Rubio
Juan C
JC
Andreu
Antoni L
AL
Martín
Miguel A
MA
Arenas
Joaquín
J
D000185:Actinin / Q000235:genetics*; D000328:Adult; D000483:Alleles; D041321:Chromosomes, Human, X; D015444:Exercise; D005080:Exercise Test; D005260:Female; D005838:Genotype; D006012:Glycogen Storage Disease Type V / Q000235:genetics* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010641:Phenotype; D012727:Sex Characteristics
C118456:ACTN3 protein, human; D000185:Actinin