Kcnj11 Gene Polymorphism And Endurance Performance Status In Hispanics: A Replication Study

Abstract

Previous reports from our laboratory had shown significant associations between the potassium inwardly-rectifying channel, subfamily J, member 11 (KCNJ11) gene Glu23Lys variant and cardiorespiratory endurance performance (CRE) phenotypes (Padró et al. (2003), MSSE, 35(S1), 377; González et al. (2003), MSSE 35(S1), 378; Ortiz et al. 2005, MSSE 37(S1), 165). The KCNJ11 gene, is expressed in several tissues, including cardiac and skeletal muscle, where it is involved in the coupling of cell metabolism to cell electrical activity. PURPOSE: To replicate the study Ortiz et al. 2005, MSSE 37(S1), 165) and validate the findings of Padró et al. (2003), MSSE, 35(S1), 377; González et al. (2003), MSSE 35(S1), 378, by testing the association between the KCNJ11 gene Glu23Lys variant and CRE performance level in Hispanic male marathon runners (MR) using a good-sized sample size. METHODS: The subjects (n=1778) were adult Hispanic male MR that completed a 42-km road race. Fast-MR (cases; n=884) were finishers in the top third percentile. Slow MR (controls; n=894) were finishers in the lowest third percentile of their respective ages. A whole blood sample provided for the extraction of genomic DNA. The polymerase chain reaction was used to amplify the KCNJ11 gene Glu23Lys variant. Both case and control groups observed genotype frequencies met Hardy-Weinberg equilibrium expectations (X2, P≥0.05). RESULTS: The main finding showed a statistically significant (p ≤0.05) association between the KCNJ11 gene Glu23Lys variant and CRE performance level. Fast-MR (cases) showed a significant over-representation of the KCNJ11 gene Glu23Lys variant compared to slow-MR (controls), 67.4% vs. 51.5%, (p ≤0.05). CONCLUSION: The study replicated and validated previous findings of an association between the KCNJ11 gene Glu23Lys variant and cardiorespiratory endurance.