OPA1 and cardiac hypertrophy: The OPA-1 mutation induces late-onset cardiac dysfunction, with no changes in the early stages of life, whereas 12-month-old Opa1+/− mice show decreased fractional shortening, cardiac output, and myocyte contraction; by contrast, OPA-1-overexpressing mice (Opa1tg) show physiological heart hypertrophy at 9 months [85].