Spinal Muscular Atrophy
What are the symptoms?
Character-istically, the legs are more severely affected than the arms. Additionally the proximal muscles (those closer to the body) are more severely affected than the distal ones (those closer to the hands and feet). Distinct clinical syndromes can be defined on the basis of the severity of the symptoms displayed. An international classification was agreed in Summer 1990 as follows:
Severe SMA - unable to sit unsupported (also known as Werdnig-Hoffmann disease or Type 1)
Intermediate SMA - able to sit unsupported, unable to stand or walk unaided (also known as Type 2)
Mild SMA - able to stand and walk unaided (also known as Kugelberg-Welander disease or Type 3).
Background
| Inheritance patterns and prenatal diagnosis ![]()