What role does ACTN3 play in Haut?

The question about ACTN3's role in skin is unusual because this gene is primarily expressed in muscle tissue. ACTN3 encodes alpha-actinin-3, a structural protein of Z-discs in fast-twitch (type II) muscle fibers. Numerous studies link the ACTN3 R577X polymorphism to athletic performance, especially sprint and power sports. In skin, however, ACTN3 expression is very low or undetectable. There are no robust human data demonstrating a direct, clinically relevant function of ACTN3 in skin. Some mechanistic work examines alpha-actinins in cell migration or wound healing, but these typically involve other isoforms (ACTN1, ACTN4). Claims that ACTN3 influences skin traits like elasticity or aging lack scientific support. Direct-to-consumer genetic tests that suggest such connections overstate the evidence. In summary, ACTN3 plays no significant role in skin based on current knowledge. The evidence is unclear to absent.