SMN2 is a gene that produces a protein called survival motor neuron (SMN), which is essential for the health of motor neurons in the spinal cord. These neurons are responsible for controlling muscle movement. While SMN1 is the primary gene for producing functional SMN protein, SMN2 can also produce it, but in smaller amounts and often in a less effective form. Mutations in the SMN1 gene lead to spinal muscular atrophy (SMA), a genetic disorder that affects muscle strength and movement. The presence of SMN2 can influence the severity of SMA, as individuals with more copies of the SMN2 gene may experience milder symptoms due to the additional production of SMN protein.