Spinal muscular atrophy type 3 (SMA type 3) is a genetic disorder that affects the motor neurons in the spinal cord, leading to muscle weakness and atrophy. It is caused by a deficiency of the survival motor neuron (SMN) protein, which is essential for the health of motor neurons. Symptoms typically appear in childhood or early adulthood and may include difficulty walking, muscle weakness, and reduced muscle tone. Individuals with SMA type 3 often have a normal life expectancy, but the severity of symptoms can vary widely. While some may require mobility aids, others can maintain independent movement. Early diagnosis and supportive therapies can help improve quality of life.