Table 1. Demographic and clinical characteristics of the SMA patients.

Characteristic	Total (n=33)	Type 1 (n=15)	Type 2 (n=16)	Type 3 (n=2)
Sex, males:females	12:21	7:8	4:12	1:1
Age at symptom onset, mean (range), months	14.7 (0.1–96)	3.9 (0.1–24)	17.8 (3–36)	72 (48–96)
Initial presentation
Respiratory difficulty	16 (49%)	3 (20%)	13 (82%)	0
Hypotonia	10 (30%)	9 (60%)	1 (6%)	0
Gait disturbance	5 (15%)	1 (7%)	2 (12%)	2 (100%)
Developmental delay	2 (6%)	2 (13%)	0	0

Except where indicated otherwise, data are n (%) values.

SMA: spinal muscular atrophy.