Extracellular RNA Biomarkers of Myotonic Dystrophy

Inclusion Criteria:

* Subjects with DM1 or DM2 based on genetic testing and/or clinical criteria (some subjects who have positive genetic testing may be asymptomatic, while other subjects who show characteristic clinical features may have declined to have genetic testing done). Control non-DM subjects are unknown to have DM or any other muscular dystrophy by history and may have had no genetic testing.
* Able to provide informed consent or assent for participation in the study.
* Demographic characteristics for single biofluid collection: Males and females age 5 years and older (DM1, DM2, and non-DM).
* Demographic characteristics for repeated measurements: Males and females age 14 years and older with DM1.
* Demographic characteristics for biofluid and muscle biopsy: Males and females, ages 18-65 years.

Exclusion Criteria:

* Medical history of any of the following. State of immunosuppression; coagulopathy; pre-existing liver or kidney disease; documented HIV positive; documented hepatitis B and/or C positive.
* Medications and other drugs. Use of anti-platelet drugs within 7 days prior to blood draw or biopsy; use of anticoagulants within 60 days prior to blood draw or biopsy; active drug or alcohol use or dependence that, in the opinion of the biopsy surgeon, would interfere with post-procedure wound care.
* Other. Women that are pregnant, or intend to become pregnant, prior to the biopsy; urine pregnancy test that is positive; inability or unwillingness of the subject to give written informed consent.
* Other. Inability or unwillingness of the subject to give written informed consent or assent.