Comparison of Muscle-Specific Creatine Kinase (CK-MM) Gene Polymorphism (rs8111989) Among Professional, Amateur Athletes and Non-athlete Karatekas

Background Identification of genetic markers is one of the priority trends to perform in athletes for evaluation of their efficacy. Previous studies have revealed that CK-MM may be used as a valuable marker to reflect the magnitude of skeletal muscle destruction in response to exercise. Objectives In this study we analyzed the frequency of rs8111989CK-MM polymorphism in karatekas to find whether there is a difference among professional, amateur athletes and non- karatekas. Methods Distribution of allele and genotype frequencies of the muscle specific creatine kinase (CK-MM) gene A/G polymorphism was assessed in a survey among 275 athletes residing in state of Isfahan (86 professional karatekas (43 male and 43 female) and 86 amateur karatekas (50 male and 36 female) and 103 non-athlete individuals (50 male and 53 female). Blood samples were taken and genotyping was performed by restriction fragment length polymorphism (RFLP) approach. Statistical analyses carried out using SPSS software and data with P < 0.05 were considered to be significant. Results The CK-MM AG genotype frequency was significantly higher in professional and amateur karate athletes and control subjects (AG genotype: 52.4% vs. AA genotype: 33.4%; GG genotype: 14.1%; χ² = 16.79, P < 0.05). Furthermore, the CK-MM genotype in the professional group (AA:31.3%, AG:56.9, GG:11.6) was different of those observed for amateur karatekas (AA:32.5%, AG:43.0, GG:24.4)(χ² = 11.39; P = 0.003) and CK-MM genotype in the amateur group was also different from non-athletes (AA:36%, AG: 56.3, GG: 7.7)(χ² = 11.39; P = 0.003). Conclusions The CK-MM gene A/G polymorphism is associated with the physical performance levels of karatekas.