ICD-11 classes
08 Diseases of the nervous system
Motor neuron diseases or related disorders
8B61 — Spinal muscular atrophy
8B61.3 — Adult onset spinal muscular atrophy, Type IV

ICD-11 8B61.3 — Adult onset spinal muscular atrophy, Type IV

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.

The diagnosis includes nothing.

The diagnosis excludes nothing.

It has no clarifying diagnoses.