Genotyping Identifies Superior Athletes

Elite sprinters were less likely to be α-actinin-3 deficient than were controls or elite endurance athletes.

Certain physical characteristics seem to facilitate athletic performance: Picture tall basketball players, thin marathon runners, and bulky football linesmen. However, the molecular basis of these advantages has been only the subject of speculation. These investigators examined the association between athletic performance and the skeletal-muscle actin-binding protein α-actinin-3. There are 2 α-actinin genes: ACTN2 is expressed in all muscle fibers, and ACTN3 expression is restricted to fast-twitch (type 2) muscle fibers. A functioning ACTN3 gene provides extra muscle protein, but absence of the protein is not lethal.

The investigators genotyped 436 unrelated white controls and 301 elite white athletes who excelled in either sprint/power or e…

Reviewing Author

Sandra Ann Carson, MD