	Infantile^a SMA Patients (n=23)	Infantile Matched Non-SMA Patients (n= 23)	Childhood Onset^b SMA Patients (n=22)	Childhood Onset-Matched Non-SMA Patients (n= 22)	Late Onset^c SMA Patients (n=296)	Late Onset-Matched Non-SMA Patients (n= 296)
Age (yrs), mean (SD)	0.2 (±0.14)	0.2 (±0.14)	0.9 (±0.87)	0.9 (±0.87)	52.2 (±21.95)	52.1 (±21.90)
Male, %	52.2	52.2	63.6	63.6	54.4	54.4
Post-index enrollment (months), mean (SD)	11.0 (±9.58)	23.8 (±18.5)	27.7 (±23.37)	33.5 (±32.04)	36.0 (±26.50)	36.3 (±29.81)