Scientists hunt for genetic and environmental triggers of rare muscle diseases

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

* Recruitment into the study is by invitation. INCLUSION CRITERIA: For the primary autoimmune and myositis study populations, children (less than 18 years of age) or adults (18 or more years of age) require a diagnosis of myositis or a related autoimmune or rheumatic disorder. Family members need to be blood relatives of the proband with the diagnosis of an autoimmune disease. Normal volunteers will be gender- and race-matched to a subset of autoimmune subjects as controls needed for specific studies. Normal volunteers should be in good health, without a recognized systemic rheumatic disorder or other autoimmune disease, and should not be taking anti-inflammatory medicines, including nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids. For all subjects: ability of the subject or parents/legal guardians to provide informed consent to all aspects of the study after full protocol information is provided. Patients enrolling in the MYOVISION national myositis patient registry were diagnosed with adult or juvenile DM, PM, IBM, or another form of myositis; resided within the United States or Canada at the time of diagnosis, and provided informed consent and completed the study questionnaires, either on paper or online. In the case of children \<18 years of age, the parent or legal guardian provided informed consent and completed the study questionnaires. EXCLUSION CRITERIA: Exclusion criteria for all protocol subjects: 1. medical illness that in the judgment of the investigators does not allow safe blood draws or other clinical evaluations needed for study participation; 2. cognitive impairment; 3. inability to give informed assent or consent. Exclusion criteria for normal volunteers: Recognized systemic rheumatic disorder or other autoimmune disease, history of cancer or taking anti-inflammatory medicines, including nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids, severe trauma, infections or vaccinations within 8 weeks. Exclusion criteria for patients in the MYOVISION national myositis patient registry were subjects with cognitive impairment and those unable to or unwilling to give informed consent,or failing to meet the inclusion criteria of the study.