Spinal muscular atrophy symptom

Editors-in-Chief: C. Michael Gibson, M.S., M.D.; Priyamvada Singh, MBBS

Infantile SMA is the most severe form. Some of the symptoms include:
 * muscle weakness
 * poor muscle tone
 * weak cry
 * limpness or a tendency to flop
 * difficulty sucking or swallowing
 * accumulation of secretions in the lungs or throat
 * legs that tend to be weaker than the arms
 * hypotonia, areflexia, and multiple congenital contractures (arthrogryposis) associated with loss of anterior horn cells
 * feeding difficulties
 * increased susceptibility to respiratory tract infections
 * developmental milestones, such as lifting the head or sitting up, can't be reached.

In general, the earlier the symptoms appear, the shorter the life span. The onset is sudden and dramatic. Once symptoms appear the motor neuron cells quickly deteriorate shortly after. The disease can be fatal and there is no cure for SMA yet known. The major management issue in Type 1 SMA is the prevention and early treatment of respiratory infections; pneumonia is the cause of death in the majority of the cases. Infants with Type 1 SMA have a life expectancy of less than two years, however, some grow to be adults. Intellectual and later, sexual functions, are unaffected by SMA.