# What is spinal muscular atrophy (SMA)?
Keywords: spinal muscular atrophy, SMA, genetic neuromuscular disease, survival motor neuron 1 gene, diagnosis, testing, inheritance, types of SMA

> Spinal muscular atrophy (SMA) is a rare genetic neuromuscular disease caused by mutations in the SMN1 gene, affecting motor function. This page provides an overview of SMA, its causes, types, inheritance patterns, and diagnostic methods.

## Details
- [Overview](#): SMA is a rare genetic neuromuscular disease affecting motor neurons.
- [What causes SMA?](#): SMA is caused by a mutation in the survival motor neuron 1 (SMN1) gene.
- [Types of SMA](#): SMA types are categorized based on age of onset and functional ability, with varying severity.
- [How is SMA inherited?](#): SMA is an inherited disease with a clear genetic cause.
- [Diagnosis and Testing](#): Genetic testing is essential to confirm a suspected SMA diagnosis.
- [About Together in SMA](#): Biogen supports SMA patients and their care teams by providing up-to-date information and resources.