Orphanet: Monomelic amyotrophy

Search for a rare disease

* (*) mandatory field

Other search option(s)

Suggest an update

(*) Required fields.


Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed.

Captcha image

Monomelic amyotrophy

Disease definition

Monomelic amyotrophy (MA) is a rare benign lower motor neuron disorder characterized by muscular weakness and wasting in the distal upper extremities during adolescence followed by a spontaneous halt in progression and a stabilization of symptoms.


Classification level: Disorder
  • Synonym(s):
    • Benign focal amyotrophy
    • Hirayama disease
    • JMADUE
    • Juvenile muscular atrophy of distal upper extremity
    • Juvenile muscular atrophy of the distal upper limb
  • Prevalence: Unknown
  • Inheritance: Unknown 
  • Age of onset: Adolescent, Adult
  • ICD-10: G12.8
  • OMIM: 602440
  • UMLS: C1865384
  • MeSH: C538253
  • GARD: 9697
  • MedDRA: 10069681

Detailed information


The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.