Genotypes Of The Skeletal Muscle Creatine Kinase Gene And Exertional Rhabdomyolyis

A polymorphism in the 3' untranslated region of the gene for the muscle-specific creatine kinase (CKMM) enzyme has been associated with differential responses to aerobic training, running economy, and serum CK levels after exercise. Whether this polymorphism is associated with susceptibility to clinically diagnosed exertional rhabdomyolysis (ER) has not been examined. PURPOSE: To determine the relationship between CKMM genotypes and ER among a physically active population METHODS: The distribution of CKMM genotypes was compared in 51 persons with a clinical diagnosis of ER and a control group of 132 participants who had never had ER. RESULTS: Among the ER cases 27% had the GG genotype as compared to 11% in the control group respectively. Likewise only 29% of the ER cases had the AA genotype as compared to 42% of controls (Chi Square = 7.57; P = 0.02). CONCLUSIONS: These results suggest that the GG genotype may predispose to ER relative to the AA genotype or that the AA genotype may be protective. The CKMM gene, in combination with perhaps a number of other genes, may be one of the multiple factors that precipitate an episode of ER.