Oxidative Capacity and Exercise Tolerance in Ambulatory SMA

Spinal Muscular Atrophy (SMA) is a progressive, recessively-inherited neuromuscular disease
characterized by weakness and muscle atrophy due to the loss of spinal cord motor neurons.
The results from this study would provide preliminary data, using non-invasive methods, on
oxidative capacity in ambulatory SMA patients and disease controls to aid in the design of
exercise intervention studies. Furthermore, this information would link previous laboratory
and preclinical findings of mitochondrial depletion in SMA to the clinical condition and
provide important information for future studies designed to improve oxidative capacity and
fitness in SMA patients.

Inclusion Criteria:

1. One of the following categories:

- Genetic confirmation of SMA with laboratory documentation of homozygous deletion
of SMN1 exon 7;

- Genetic confirmation of mitochondrial myopathy or evidence from muscle biopsy
confirming the diagnosis; or

- Healthy individuals.

2. Able to walk independently at least 25 meters, and able to tread a stationary cycle
ergometer.

Exclusion Criteria:

1. Unable to walk 25 meters independently.

2. Use of investigational medications intended for the treatment of SMA within 30 days
prior to study entry.

3. The presence of any contraindication to exercise according the ACSM criteria.

Patients with and without Spinraza treatment are eligible.