8B61

ICD-11 MMS 2026-01

Spinal muscular atrophy

Description

Spinal muscular atrophy (SMA) is a progressive disorder with loss of anterior horn cells leading to muscle weakness and wasting. The weakness is typically symmetrical. Typically, upper motor neuron signs are absent and there is no sensory deficit. Feeding and swallowing can be affected, and involvement of respiratory muscles may occur. SMA is an autosomal recessive disorder linked to chromosome 5q13 and the disorder is caused by deletion or mutation of SMN 1 (spinal motor neuron 1) gene. The four types of SMA I, II, III and IV are categorised based on the age of onset of the disease and the ability to achieve motor milestones.

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

Child 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
  • 8B61.3 – 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

Sibling codes

  • 8B60 – Motor neuron disease
  • 8B62 – Post polio progressive muscular atrophy
  • 8B6Y – Other specified motor neuron diseases or related disorders
  • 8B6Z – Motor neuron diseases or related disorders, unspecified

Foundation entity

Spinal muscular atrophy – http://id.who.int/icd/entity/71074342

Allowed postcoordination axes

Part of: 08: Diseases of the nervous system