U.S. flag

An official website of the United States government


Send to:

Choose Destination

Familial idiopathic inflammatory myopathy(IIM)

MedGen UID:
Concept ID:
Disease or Syndrome
Synonyms: Idiopathic inflammatory myopathy, familial; Idiopathic myopathy; Myopathy, familial idiopathic inflammatory
Monarch Initiative: MONDO:0600024
OMIM®: 160750


An instance of myositis that is caused by an inherited genomic modification in an individual, and has an unknown cause. [from MONDO]

Clinical features

From HPO
Proximal muscle weakness
MedGen UID:
Concept ID:
A lack of strength of the proximal muscles.
Myositis disease
MedGen UID:
Concept ID:
Disease or Syndrome
Idiopathic inflammatory myopathy is a group of disorders characterized by inflammation of the muscles used for movement (skeletal muscles). Idiopathic inflammatory myopathy usually appears in adults between ages 40 and 60 or in children between ages 5 and 15, though it can occur at any age.\n\nThe primary symptom of idiopathic inflammatory myopathy is muscle weakness, which develops gradually over a period of weeks to months or even years. Other symptoms include joint pain and general tiredness (fatigue).\n\nIn sporadic inclusion body myositis, the muscles most affected are those of the wrists and fingers and the front of the thigh. Affected individuals may frequently stumble while walking and find it difficult to grasp items. As in dermatomyositis and polymyositis, swallowing can be difficult.\n\nThere are several forms of idiopathic inflammatory myopathy, including polymyositis, dermatomyositis, and sporadic inclusion body myositis.\n\nPolymyositis and dermatomyositis involve weakness of the muscles closest to the center of the body (proximal muscles), such as the muscles of the hips and thighs, upper arms, and neck. People with these forms of idiopathic inflammatory myopathy may find it difficult to climb stairs, get up from a seated position, or lift items above their head. In some cases, muscle weakness may make swallowing or breathing difficult.\n\nPolymyositis and dermatomyositis have similar symptoms, but dermatomyositis is distinguished by a reddish or purplish rash on the eyelids, elbows, knees, or knuckles. Sometimes, abnormal calcium deposits form hard, painful bumps under the skin (calcinosis).

Professional guidelines


Roy B, Peck A, Evangelista T, Pfeffer G, Wang L, Diaz-Manera J, Korb M, Wicklund MP, Milone M, Freimer M, Kushlaf H, Villar-Quiles RN, Stojkovic T, Needham M, Palmio J, Lloyd TE, Keung B, Mozaffar T, Weihl CC, Kimonis V
Ann Clin Transl Neurol 2023 May;10(5):686-695. Epub 2023 Apr 7 doi: 10.1002/acn3.51760. PMID: 37026610Free PMC Article
Leung AKC, Lam JM, Alobaida S, Leong KF, Wong AHC
Curr Pediatr Rev 2021;17(4):273-287. doi: 10.2174/1573396317666210426105045. PMID: 33902423
Pignolo RJ, Shore EM, Kaplan FS
Pediatr Endocrinol Rev 2013 Jun;10 Suppl 2(0 2):437-48. PMID: 23858627Free PMC Article

Recent clinical studies


Rider LG, Gurley RC, Pandey JP, Garcia de la Torre I, Kalovidouris AE, O'Hanlon TP, Love LA, Hennekam RC, Baumbach LL, Neville HE, Garcia CA, Klingman J, Gibbs M, Weisman MH, Targoff IN, Miller FW
Arthritis Rheum 1998 Apr;41(4):710-9. doi: 10.1002/1529-0131(199804)41:4<710::AID-ART19>3.0.CO;2-K. PMID: 9550481

Supplemental Content

Table of contents

    Clinical resources

    Practice guidelines

    • PubMed
      See practice and clinical guidelines in PubMed. The search results may include broader topics and may not capture all published guidelines. See the FAQ for details.

    Consumer resources

    Recent activity

    Your browsing activity is empty.

    Activity recording is turned off.

    Turn recording back on

    See more...