Orphanet: Immune mediated necrotizing myopathy

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.

Orphanet doesn't provide personalised answers. To get in touch with the Orphanet team, please contact

Information provided in your contribution (including your email address) will be stocked in .CSV files that will be sent as an email to Orphanet's teams. These emails might be conserved in the teams' mailboxes, in our backoffice servers but will not be registered in our databases (for more information see our section General Data Protection Regulation and data privacy (GDPR) and Confidentiality).

Captcha image

Immune-mediated necrotizing myopathy

Disease definition

A rare form of idiopathic inflammatory myopathy characterized by acute or subacute, severe, symmetrical, proximal muscle weakness usually associated with muscle-specific antibodies (anti-HMGCR or anti-SRP). Histopathological characteristics include myocyte necrosis and regeneration without significant inflammation, and C5b-9 deposition on non-necrotic myofibers.


Classification level: Disorder
  • Synonym(s):
    • Anti-HMG-CoA myopathy
    • Anti-SRP myopathy
    • Autoimmune necrotizing myositis
    • IMNM
    • Immune myopathy with myocyte necrosis
    • NAM
  • Prevalence: Unknown
  • Inheritance: Not applicable 
  • Age of onset: Adult, Elderly, Childhood, Adolescent
  • ICD-10: G72.4
  • OMIM: -
  • UMLS: C3267047
  • MeSH: -
  • GARD: -
  • MedDRA: -

Detailed information

General public


ERN : produced/endorsed by ERN(s)
FSMR : produced/endorsed by FSMR(s)
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.