The goal of this observational study is to to establish profiles of clinical progression in patients affected by the different types of SMA (type I, II and III) treated with the currently approved drugs using a structured battery of clinical tests.

Another goal of the study is to assess the progression of the disease in patients identified through neonatal screening.

The collection of 2-year longitudinal clinical data will be conducted in newly treated patients at baseline, 6-, 12-, 14- and 22-months post-treatment. Parameters will include motor function, fatigability, respiratory function, event-free survival and death, and swallowing and feeding modalities. It is anticipated that at least 30 new patients will be enrolled in the study.

Importantly, information will also be collected on patients who may decide to switch treatment during the duration of our study, trying to establish if the switch to a new drug (or as an add-on should patients take a new treatment after being treated with gene therapy) may be associated with changes in clinical phenotype.

The aim is to apply a newly established clinical protocol that allows identifying minor signs of disease that are easily missed in the absence of an NBS-detected diagnosis. Indeed, not all infants identified as SMA-positive through the NBS are truly asymptomatic, as a proportion of them may appear paucisymptomatic and their minor signs could be possibly not detected in the absence of a positive screening test.

Inclusion Criteria:

• All SMA patients

Exclusion Criteria:

• Inability to understand or to provide informed consent.

Patients with spinal muscular atrophy regardless of age, type of SMA or treatment