Synonyms: Adult-onset overlap myositis | Non-specific myositis
A rare idiopathic inflammatory myopathy (IIM) with a heterogeneous phenotype characterized by myositis with at least one clinical and/or autoantibody overlap feature. Possible clinical overlap features include polyarthritis Raynaud’s phenomenon sclerodactyly scleroderma (proximal to metacarpophalangeal joints) lung interstitial pneumonia and/or clinical signs of systemic lupus erythematosus (SLE).
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version April 2026
Newly diagnosed with
Overlap myositis?
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Advocacy Organizations
Association Aux Pas du Coeur – Côte d’ivoire
Our organization wants to raise awareness and recognition of rare diseases in Ivory Coast. Our mission is to: Raise awareness and campaign to help with the diagnosis and free therapeutic care of patients. Request and/or contribute to actions relating to the training of the medical profession to be able to make a final diagnosis and ensure continuous monitoring of patients easily.
Born a Hero, Research Foundation
Our mission is to accelerate innovation and research to improve the quality of life for patients with FGFR Syndromes, including Pfeiffer Syndrome.
Fundacion Powerchair Football Argentina
To develop Powerchair Football in Argentina in order to integrate people with motor disabilities (SMA, Duchenne muscular dystrophy, Achondroplasia, Rare Diseases) into sports practice and to promote their social inclusion, based on empowerment, independence, and the creation of new bonds and friendships.
Myositis Support and Understanding
The Mission of Myositis Support and Understanding is to improve the lives of and empower those fighting myositis through education, support, awareness, advocacy, and access to research.
Neuromuscular Disease Foundation
The Neuromuscular Disease Foundation's (NDF) mission is to enhance the quality of the lives of people living with GNE Myopathy (also known as HIBM) through advocacy, education, outreach, and funding clinical research focused on treatments and a cure.
The Myositis Association (TMA)
The mission of The Myositis Association (TMA) is to improve the lives of persons affected by myositis, fund innovative research, and increase myositis awareness and advocacy. Our programs and services provide information, support, advocacy, and research for the worldwide myositis community.
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Clinical Trials
For a list of clinical trials in this disease area, please click here.