There are several classifications of SMA, of which the ages, signs and symptoms may overlap. Type I or Infantile SMA, also called Werdnig-Hoffman Disease, is the most severe form. A child may be symptomatic at birth and the diagnosis is made in the first year of life. Normal reflexes are absent. Progressive floppiness of muscles, arms and legs, thin muscle mass and generalized weakness is seen.
Intelligence is normal.
These children have fewer feeding and breathing problems. Type III SMA is the mildest form. It is also known as Kugelberg Welander Disease. This, too, is a more chronic or juvenile form. There is no medical treatment to delay progression of Spinal Muscular Atrophy.