# What is spinal muscular atrophy (SMA)?
Keywords: spinal muscular atrophy, SMA, genetic mutation, SMN1 gene, neuromuscular disease, diagnosis, genetic testing

> Spinal muscular atrophy (SMA) is a rare genetic neuromuscular disease caused by a mutation in the SMN1 gene. This page provides information about SMA, its causes, types, inheritance, diagnosis, and testing, along with resources for patients and caregivers.

## Details
- [What causes SMA](#): SMA is caused by a mutation in the survival motor neuron 1 (SMN1) gene.
- [Types of SMA](#): SMA is categorized into different types based on age of onset and functional ability, with varying severity within each type.
- [How is SMA inherited](#): SMA is an inherited disease with a clear genetic cause.
- [Diagnosing and testing](#): Genetic testing is essential for confirming an SMA diagnosis.
- [About Together in SMA](#): Biogen provides resources to support SMA patients and their care teams, aiming to improve care and facilitate conversations with doctors.