Core Concepts in Human Genetics: Understanding the Complex Phenotype of Sport Performance and Susceptibility to Sport Injury.

High-throughput sequencing of multiple human exomes and genomes is rapidly identifying rare genetic variants that cause or contribute to disease. Microarray-based methodologies have also shed light onto the genes that contribute to common, non-disease human traits such as hair and eye colour. Sport scientists should keep in mind several things when interpreting the literature, and when designing their own genetic studies. First of all, most genetic association methods are more powerful for detecting disease phenotypes (such as susceptibility to injury) than they are for detecting healthy phenotypes (such as sport performance). This is because there are likely to be many more biological factors contributing to the latter, and the effect size of most of these biological factors is likely to be small. Second, implicating a particular gene in a human phenotype like athletic performance or injury susceptibility requires an unbiased population data set. Third, new types of non-coding biological variability continue to be uncovered in the human genome (e.g. epigenetic modifications, microRNAs, etc.). These other types of variability may contribute significantly to differences in athletic performance.