 SPOT SMA is a prospective NIH-supported clinical study targeting pre-symptomatic or recently diagnosed infants and children with Spinal Muscular Atrophy SMA types 1, 2, or 3 and their healthy control siblings less than 36 months of age at the time of study enrollment. The main objective of the study is to prospectively collect longitudinal clinical outcomes and provide counseling and education to parents of newly diagnosed children. The study will assess the impact of current standard of care management paradigms and interventions on health outcomes in newly diagnosed SMA infants and children with type 1, 2 or 3 and age appropriate controls. There is no investigational drug and no specific intervention in this study. Rather, the investigators will document outcomes related to current therapies provided to participating subjects, and will educate participants about possible clinical trial opportunities. 