8B61.3

ICD-11 MMS 2026-01

Adult onset spinal muscular atrophy, Type IV

Description

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 IV
  • adult onset SMA - [spinal muscular atrophy], Type IV
  • type 4 SMA - [spinal muscular atrophy]

Exclusions from above levels

  • 05 – Endocrine, nutritional or metabolic diseases
  • 18 – Complications of pregnancy, childbirth and the puerperium
  • 19 – Certain conditions originating in the perinatal period
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  • 22 – Injury, poisoning or certain other consequences of external causes

Sibling codes

  • 8B61.0 – Infantile spinal muscular atrophy, Type I
  • 8B61.1 – Late infantile spinal muscular atrophy, Type II
  • 8B61.2 – Juvenile form spinal muscular dystrophy, Type III
  • 8B61.4 – Localised spinal muscular atrophy
  • 8B61.Y – Other specified spinal muscular atrophy
  • 8B61.Z – Spinal muscular atrophy, unspecified

Foundation entity

Adult onset spinal muscular atrophy, Type IV – http://id.who.int/icd/entity/443229384

Allowed postcoordination axes

Part of: 8B61: Spinal muscular atrophy › 08: Diseases of the nervous system