Myotonic dystrophy
DM1 and DM2 genetics and anticipation, the multisystem picture behind grip myotonia, cardiac conduction surveillance and sudden death, anaesthetic risk, and congenital DM through the mother.
Tier 1Condition
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- The commonest adult muscular dystrophy: historically about 1 in 8,000, but newborn genetic screening suggests up to about 1 in 2,100 (Johnson 2021). Autosomal dominant, with anticipation.
- DM1 (DMPK CTG) is distal, facial and congenital-capable. DM2 (CNBP CCTG) is proximal, painful and milder.
- Multisystem: myotonia, cataract, cardiac conduction disease, insulin resistance, hypogonadism, hypersomnolence and respiratory failure.
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Sources
- Consensus-based care recommendations for adults with myotonic dystrophy type 1 (Ashizawa T et al. Neurol Clin Pract 2018;8:507-20)Myotonic Dystrophy Foundation, 2018
- Consensus-based care recommendations for adults with myotonic dystrophy type 2 (Schoser B et al. Neurol Clin Pract 2019;9:343-53)Myotonic Dystrophy Foundation, 2019
- Consensus-based care recommendations for cardiologists treating adults with myotonic dystrophy type 1Myotonic Dystrophy Foundation, 2026 page update
- Clinical care recommendations for cardiologists treating adults with myotonic dystrophy (McNally EM et al. J Am Heart Assoc 2020;9:e014006)Journal of the American Heart Association, 2020
- Population-based prevalence of myotonic dystrophy type 1 using genetic analysis of statewide blood screening program (Johnson NE et al. Neurology 2021;96:e1045-53)Neurology, 2021
- 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapyEuropean Society of Cardiology, 2021
- Electrocardiographic abnormalities and sudden death in myotonic dystrophy type 1 (Groh WJ et al. N Engl J Med 2008;358:2688-97)New England Journal of Medicine, 2008
- Electrophysiological study with prophylactic pacing and survival in adults with myotonic dystrophy and conduction system disease (Wahbi K et al. JAMA 2012;307:1292-301)JAMA, 2012
- Bird TD. Myotonic dystrophy type 1. GeneReviews (CTG repeat over 34 abnormal)University of Washington, Seattle (GeneReviews)
- Assessing Fitness to Drive for commercial and private vehicle driversAU/NZAustroads and National Transport Commission, 2022
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy