What role does ACTN3 play in fertility?

ACTN3 is primarily known for its role in fast-twitch muscle fibers, with the common R577X polymorphism affecting athletic performance. Its role in fertility is less established. Some studies have investigated ACTN3 expression in sperm and its potential impact on sperm motility, but evidence is limited and not conclusive. There is no strong clinical or genetic evidence that ACTN3 variants directly influence human fertility. The gene is not included in standard fertility panels. Therefore, while a speculative link exists, it remains an area of ongoing research rather than a proven factor. Consumers should be cautious about overinterpreting any such claims from direct-to-consumer genetic tests.