8B61.3

Adult onset spinal muscular atrophy, Type IV

Atrofia muscular espinal de início no adulto, tipo IV

Category

Definition

In SMA type 4 weakness, most commonly develops after 35 years of age (less commonly between 18 to 35 years old). Weakness of proximal muscles is more prominent in the legs than in the arms. Insidious onset and very slow progression are the characteristic features, and life span is normal.

Index Terms

Adult onset spinal muscular atrophy, Type IVadult onset SMA - [spinal muscular atrophy], Type IVtype 4 SMA - [spinal muscular atrophy]