8B61.0

ICD-11 MMS 2026-01

Infantile spinal muscular atrophy, Type I

Description

In SMA type 1, onset of weakness may be prenatal (decreased fetal movements toward the end of pregnancy) or within the first six months of life. Infants demonstrate a characteristic frog position with the thighs externally rotated and abducted and the knees flexed (floppy infant). Bulbar weakness causes feeding difficulty. Children are never able to sit without support, and the average survival is 9 months; survival beyond 2 years is rare.

Index terms

  • Infantile spinal muscular atrophy, Type I
  • Werdnig-Hoffman muscular atrophy
  • Werdnig-Hoffmann Disease
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  • infantile SMA - [spinal muscular atrophy], Type I
  • Infantile spinal muscular atrophy with respiratory distress type 1
  • SMARD 1 - [Infantile spinal muscular atrophy with respiratory distress type 1]

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

  • 8B61.1 – Late infantile spinal muscular atrophy, Type II
  • 8B61.2 – Juvenile form spinal muscular dystrophy, Type III
  • 8B61.3 – Adult onset spinal muscular atrophy, Type IV
  • 8B61.4 – Localised spinal muscular atrophy
  • 8B61.Y – Other specified spinal muscular atrophy
  • 8B61.Z – Spinal muscular atrophy, unspecified

Foundation entity

Infantile spinal muscular atrophy, Type I – http://id.who.int/icd/entity/915903258

Allowed postcoordination axes

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