Spinal muscular atrophy (SMA) is one of 7,000 rare diseases. It is the second-most common autosomal recessive disease in humans and the number one genetic cause of death in infancy. Making an SMA diagnosis as early as possible is crucial to infant health. Early treatment will offer a better likelihood of long-term success if an infant becomes symptomatic.
About 98% of patients with SMA have the same genetic mutation. Newborn screening identifies the disease-causing mutation in the SMN1 gene and the number of copies of the SMN2 gene, which can help physicians anticipate the severity of the phenotype.