The full name of sma is spinal muscular atrophy, a hereditary spinal muscular atrophy disease, there are four types, and the early manifestations of the affected children are mainly muscle weakness and so on. Spinal muscular atrophy type I is known as the infantile form. The disease usually starts within 6 months after birth, with rapidly developing progressive, symmetrical weakness of the limbs, with muscle weakness mainly in the proximal part of the limbs, as well as weakness of the oropharyngeal muscles, weak crying, and weak sucking. As the disease worsens, children may develop respiratory distress, and most die of respiratory failure within 2 years of age. Children with spinal muscular atrophy should go to the hospital as early as possible for a definitive diagnosis, and intervention should be initiated as soon as possible under the guidance of the doctor.