MUSCLE-SPECIFIC CREATINE-KINASE GENE POLYMORPHISMS IN ELITE ENDURANCEATHLETES AND SEDENTARY CONTROLS

The purpose of this study was to investigate the association between e lite endurance athlete (EEA) status and two restriction fragment lengt h polymorphisms (RFLPs) at the muscle-specific creatine kinase (CKMM) gene locus. Genomic DNA was extracted from white blood cells or lympho blastoid cell lines of 124 unrelated Caucasian male EEA (V) over dot O -2max >73 mL.kg(-1).min(-1)) and 115 unrelated Caucasian sedentary mal e controls (SCON). The genetic polymorphism at the CKMM locus was dete cted by the polymerase chain reaction and DNA digestion with the Ncol and Taql restriction endonucleases. The allelic frequencies for the Nc oI and TaqI RFLPs were not different (P > 0.05) between EEA and SCON s ubjects. The three expected genotypes for CKMM-NcoI (1170/1170 bp, 117 0/985 +185 bp, and 985 + 185/985 + 185 bp) and CKMM-TaqI (1170/1170 bp , 1170/1020 + 150 bp, and 1020 + 50/1020 + 150 bp) were observed in th e EEA and SCON groups. These genotype frequencies were in Hardy-Weinbe rg equilibrium, but they were not significantly (P > 0.05) different b etween the EEA and SCON. A strong (P < 0.001) linkage disequilibrium w as detected among the NcoI and TaqI RFLPs in both EEA and SCON. These findings indicate that the skeletal muscle CK-NcoI and CK-TaqI gene po lymorphisms are not associated with the elite endurance athlete status .