Spinal Muscular Atrophy Type 2
(also known as "spinal muscular atropy type II") is an autosomal recessive
disease and is a form of spinal muscular atrophy
Children with spinal muscular atrophy type 2 manifest less severe weakness than children with Werdnig-Hoffman disease
. Symptoms are usually noticed later in life, usually between the age of 6 to 18 months. The clinical features are similar to those found in children with Type 1; in fact, there are many children for whom the characterization of Type 1 (Werdnig-Hoffman) or Type 2 SMA becomes a "best guess". Children with Type 2 SMA usually achieve the ability to sit independently, however, they almost never achieve the ability to walk or stand without support.
Some children with SMA Type 2 have a relatively static course and remain free of life threatening complications such as pneumonia. Other children, have progressive weakness of their swallowing and respiratory muscles. Many youngsters with SMA Type 2 develop curvature of the spine (Kyphoscoliosis) and other orthopedic problems. Skillful management by a team of physical therapists and orthopedic surgeons is usually needed to manage these problems.