Testing Youth for Sports Performance Genes

Abstract

Source: Brooks MA, Tarini BA. Genetic testing and youth sports. JAMA. 2011; 305(10): 1033– 1034; doi: 10.1001/jama.2011.286Genetic testing is currently available for a variety of reasons, from prenatal testing for congenital conditions to verification of a blood relationship. A new use, testing for “sport performance genes,” has hit the marketplace and is becoming popular with parents who envision athletic prowess in their children’s future.The alpha actinin-3 gene (ACTN3), named the “speed gene,” produces a protein that stabilizes sarcomeres during the contraction of fast-twitch fibers used in intense bursts of physical activity such as sprinting. More than half of all individuals of European descent are heterozygotes (RX). In 2003, Yang, et al,1 were the first to suggest that homozygosity of this gene could enhance athletic performance. They found 50% of “elite white sprint athletes” were homozygous (RR) for this gene compared with 31% of “elite endurance athletes.” Yang suggests that an individual is inherently predisposed toward specialist performance in one area.In 2008, a United States-based company began offering the ACTN3 test directly to coaches, parents, and athletes of all ages, suggesting that a child should focus on the athletic activity for which he or she has special ability as determined by his genome, promoting the idea that athletic performance is mainly dependent on genetics. However, the truth is that genetics is only one of many factors. Marketing of these genetic tests has occurred before there is complete understanding of what leads to superior athletic performance. Parents must be educated about genetics, its scope and its limits. The pediatrician must be encouraged to perform this important task.The authors of this JAMA editorial question whether identification of talent or genetic predisposition is appropriate in youth sports. Is it appropriate that the objective of youth sports participation be to become an elite athlete, to win at all costs? Very few youth will attain elite athlete status. Perhaps there should be more emphasis on the benefits of teamwork training, character development, social relationships, and general health and fitness? The American Academy of Pediatrics cautions that early specialization in sports could lead to injuries and burnout. 2The authors recommend that pediatric health care providers: 1) promote athletics for the benefits of general good health and fitness; 2) foster respect for a child’s self-determination to choose the athletic activity he or she enjoys; 3) make clear to parents that no single test, genetic or otherwise, can predict whether a child will become an elite athlete.Pediatricians should promote participation in physical exercise and play activities for all children, especially in view of the high incidence of childhood obesity. The goal of physical exercise ought to be first to promote good health and fitness. Subjecting a child for whom the parents’ envision elite athletic status to intense training may result in injury, fatigue, and even apathy. As advocates for children, pediatricians can step up to the plate to encourage and protect the young athlete.