Spinal muscular atrophy (SMA) is a rare genetic neuromuscular disorder that affects motor neurons, leading to progressive muscle weakness and wasting. It can manifest from infancy to adulthood, with symptoms including respiratory issues, scoliosis, and joint contractures. SMA is caused by mutations in the SMN1 gene, resulting in different types of the disease based on age of onset and severity. Types range from severe symptoms at birth (Type 0) to milder forms appearing in adulthood (Type IV). The disorder is characterized by symmetric muscle weakness, particularly in the trunk and upper limbs, with respiratory muscle involvement. SMA is linked to chromosome 5q13 and is an autosomal recessive condition. New treatments are improving outcomes, especially for Types I and II, changing the disease's natural course.