SMA type 1, or Spinal Muscular Atrophy type 1, is a genetic disorder that primarily affects infants and young children. It is caused by a deficiency of the SMN1 gene, which is essential for the survival of motor neurons in the spinal cord. This leads to muscle weakness and atrophy, making it difficult for affected individuals to perform basic movements like sitting or crawling. Symptoms of SMA type 1 usually appear within the first six months of life. Children with this condition may have trouble with head control, swallowing, and breathing. Early diagnosis and intervention, including treatments like nusinersen or onasemnogene abeparvovec, can help improve outcomes and quality of life for those affected.