Muscle Performance
Power |
Endurance |
rs1815739: C or T
CC is associated with power muscles.
TT is associated with endurance muscles.
CT is a mix.
The rs1815739 polymorphism is in the actinin 3 gene. Actinin 3 protein is a key component of muscle needed for contraction. Actinin3 crosslinks actin thin filaments in skeletal muscle type 2 (fast) fibers.
The T polymorphism results in a stop codon and prevents expression of actinin 3. Athletes with TT do not make actinin 3. Curiously, these athletes may have greater endurance than CC or CT athletes.