Genetic association research in football: A systematic review

Abstract

Genetic variation is responsible for a large amount of the inter-individual performance disparities seen in sport. As such, in the last ten years genetic association studies have become more common; with one of the most frequently researched sports being football. However, the progress and methodological rigor of genetic association research in football is yet to be evaluated. Therefore, the aim of this paper was to identify and evaluate all genetic association studies involving football players and outline where and how future research should be directed.Firstly, a systematic search was conducted in the Pubmed and SPORTDiscus databases, which identified 80 eligible studies. Progression analysis revealed that 103 distinct genes have been investigated across multiple disciplines; however, research has predominately focused on the association of the ACTN3 or ACE gene. Furthermore, 55% of the total studies have been published within the last four years; showcasing that genetic association research in football is increasing at a substantial rate. However, there are several methodological inconsistencies which hinder research implications, such as; inadequate description or omission of ethnicity and onfield positions. Furthermore, there is a limited amount of research on several key areas crucial to footballing performance, in particular; psychological related traits. Moving forward, improved research designs, larger sample sizes, and the utilisation of genome-wide and polygenic profiling approaches are recommended. Finally, we introduce the Football Gene Project, which aims to address several of these limitations and ultimately facilitate greater individualised athlete development within football.

The association of the ACTN3 R577X and ACE I/D polymorphisms with athlete status in football: a systematic review and meta-analysis

“…As a result, studies require large homogenous sample sizes in order to have sufficient statistical power and demonstrate significant associations and replications 45,47 . However, studies within football genomics have notoriously small sample sizes and many are heterogenic multi-sport studies; mainly due to the unique population and limited access available 48 . Therefore, to overcome the limitation of sample sizes and heterogeneity, a meta-analysis can be used to pool the results of single homogenous studies together 47 .…”

Genetic Testing in Professional Football: Perspectives of Key Stakeholders

“…First, this may represent an increased interest in genetic testing in sport, corresponding with the increase in sport genomic research in recent years [30]. More specifically in football, McAuley and colleagues [17] showed that 55% of genetic association studies involving football players have been published within the last 4 years. Second, this increased proportion could also illustrate a more accurate representation of the true, and larger, prevalence of genetic testing within professional football.…”

“…This may be explained by the paucity of genetic research on psychological traits in football. Indeed, a recent systematic review showcased that out of 80 genetic association studies involving football players, only three studies investigated psychological traits compared to 20 on physiological traits [17]. As such, in football, there is currently a limited psychogenetic evidence base available to key stakeholders to form their opinions on genetic associations with psychological traits.…”

“…Current research has estimated that the genetic contribution (i.e., heritability) to overall athletic status is ~ 66% [7], with the estimated genetic influence on specific performance traits ranging broadly from 30% to 80% [37]. Moreover, several genetic markers have been identified that may be associated with athlete status and specific performance-related phenotypes in football, such as the alpha-actinin-3 (ACTN3) R577X and angiotensin-I-converting enzyme (ACE) I/D polymorphisms (see [17] for a review).…”

Defining “elite” status in sport: from chaos to clarity

“…These recommendations may seem obvious, but we would note that a recent scoping review of talent research found that~15% of studies did not report gender and 22% did not report nationality (Baker et al, 2020). Indeed, inadequate reporting of participant characteristics is a common finding throughout research syntheses in sport (McAuley et al, 2020a). Overall, this greater transparency will allow readers to determine their personal classifications for samples more effectively, and thus facilitate improved research synthesis and practical interpretations.…”