Fig. 1.

WHO motor milestones at baseline and last visit for A infantile-onset and B later-onset participants. ^aIncludes motor milestones demonstrated at baseline and motor milestones gained during the study that were demonstrated at the last visit. Age categories are age at study baseline. All milestones that were achieved at baseline were maintained as of each participant’s last observed visit except for one participant in the later-onset group (aged > 6 years at enrollment) who demonstrated sitting without support at baseline and all subsequent visits except the last visit (Day 423). No other milestones have been demonstrated by this participant at baseline or any subsequent visits to date. All milestones that were gained throughout study were demonstrated at all subsequent visits with one exception. One participant in the later-onset group (aged ≤ 2 years at enrollment) demonstrated standing with assistance at Day 183 through Day 663 (last visit) with the exception of non-demonstration of this milestone at the Day 543 visit. SMA spinal muscular atrophy, WHO World Health Organization