Age at diagnosis is prognostic of outcome in RMS. Infants have poorer FFS than older patients with RMS. (A) Estimated 5-year FFS (95% CI) by age group are 57% (44%,67%) for age < 1 year, 81% (79%,93%) for age 1–9 years, and 68% (63%,72%) for age ≥ 10 years (p-value < 0.001). (B) Estimated 5-year OS (95% CI) are 76% (65%,85%) for age < 1 year, 87% (85%, 89%) for age 1–9 years, and 75% (71%–79%) for age ≥ 10 years (p-value < 0.001).