# Introduction to Spinal Muscular Atrophy (SMA)
Keywords: spinal muscular atrophy, SMA, genetic cause, motor neurons, muscle atrophy, 5q SMA, nusinersen, Spinraza

> This page provides an overview of spinal muscular atrophy (SMA), its genetic causes, clinical classification, and treatment options, including the disease-modifying therapy Spinraza.

## Details
- [Introduction](#): Spinal muscular atrophy (SMA) is a leading genetic cause of death in infants, characterized by motor neuron degeneration and muscle atrophy.
- [Genetic Cause](#): SMA is primarily caused by mutations in the SMN1 gene, with the SMN2 gene playing a modifying role; symptoms and challenges vary widely.
- [Natural History](#): Untreated SMA leads to progressive muscle degeneration and severe clinical manifestations over time.
- [Measures of Motor Function](#): Tools and methods to assess motor function in individuals with SMA.
- [SPINRAZA® Nusinersen](#): Spinraza is the first approved disease-modifying treatment for 5q SMA.