A key eligibility criterion for access to FDA-approved SMA treatments as well as qualification for clinical trials is confirmation via genetic testing of a homozygous deletion or compound heterozygous mutation of SMN1. Thus, all individuals in this study with diagnostic results would be eligible to seek treatment with an FDA approved drug for SMA or to participate in a clinical trial for this disease. This evidence concerns the gene SMN1 and proximal spinal muscular atrophy.