Myotonic Dystrophy type 1 (DM1), also known as Steinert disease, is a genetic neuromuscular disorder characterised by progressive muscle weakness and wasting [1]. DM1 is the most common form of muscular dystrophy in adults, but it also affects children. It results from a mutation in the DMPK gene. Specifically, this mutation involves a repetition of nucleotides. Additionally, this mutation is dynamic across generations (for example, parents can have 500 repeats and children can have 700 or more). Therefore, if a parent develops mild symptoms, their child may develop severe symptoms. It is often considered a rare disease due to its wide variation in prevalence [2], but in certain regions the prevalence has increased to 1 in 2,100 births [3]. This increase suggests that DM1 may be more common than previously believed, as many cases may go undiagnosed.
The hallmark of DM1 is myotonia, a condition where muscles are unable to relax normally, coupled with muscle weakness that progresses over time. However, the impact of DM1 extends far beyond the musculoskeletal system. It can affect the cardiac system, endocrine glands, the central nervous system, and more (respiratory issues, cataract, baldness, metabolic disorders), leading to a complex clinical presentation that requires comprehensive management strategies. That’s why DM1 is a multisystemic disease [1]. Due to muscle weakness, daytime sleepiness, pain and fatigue, DM1 significantly affects daily activities and independence [4, 5]. Furthermore, brain atrophy leads to cognitive deficits [6]. In children and young adults, these impairments can cause learning difficulties that hinder educational achievement. In working-age individuals, they can disrupt employment [7], lead to early retirement, and reduce financial stability. Mobility issues and other symptoms, such as somnolence, urinary problems (micturition), and gastrointestinal issues, can make participation in social activities challenging [8].
The chronic nature of DM1 can also burden personal relationships[7]. Partners, family members, and friends may all be affected by the changes in social dynamics and the increased need for care and support due to impaired social cognition [9]. Family members often become caregivers, a role that can be both emotionally and physically demanding (Figure). The progressive nature of DM1 means that caregiving responsibilities typically increase over time, which can lead to caregiver burnout. The care needs associated with DM1, including medical appointments, treatments, and home care, can lead to significant financial strain on families. This is compounded by the potential loss of income if a family member reduces work hours or stops working to provide care. Families may experience shifts in roles and responsibilities, especially as the condition progresses. The demands of caregiving and the need to accommodate the symptoms of DM1 can disrupt the social lives of family members, leading to isolation and changes in family dynamics [10].
DM1 is often better known by patients and their families than by healthcare professionals, and its social impact is frequently overlooked. Currently, there is no cure, and the lack of funding for ongoing research can be discouraging.
References
1. Wenninger, S., F. Montagnese, and B. Schoser, Core Clinical Phenotypes in Myotonic Dystrophies. Front Neurol, 2018. 9: p. 303.
2. Liao, Q., et al., Global Prevalence of Myotonic Dystrophy: An Updated Systematic Review and Meta-Analysis. Neuroepidemiology, 2022. 56(3): p. 163-173.
3. Johnson, N.E., et al., Population-Based Prevalence of Myotonic Dystrophy Type 1 Using Genetic Analysis of Statewide Blood Screening Program. Neurology, 2021. 96(7): p. e1045-e1053.
4. Raymond, K., et al., Predictors of participation restriction over a 9-year period in adults with myotonic dystrophy type 1. Disabil Rehabil, 2022. 44(12): p. 2615-2631.
5. Dauvilliers, Y.A. and L. Laberge, Myotonic dystrophy type 1, daytime sleepiness and REM sleep dysregulation. Sleep Med Rev, 2012. 16(6): p. 539-45.
6. Morin, A., et al., Unravelling the impact of frontal lobe impairment for social dysfunction in myotonic dystrophy type 1. Brain Commun, 2022. 4(3): p. fcac111.
7. Baldanzi, S., et al., Hard ways towards adulthood: the transition phase in young people with myotonic dystrophy. Acta Myol, 2016. 35(3): p. 145-149.
8. Maagdenberg, S.J.M., et al., Impact of gastrointestinal and urological symptoms in children with myotonic dystrophy type 1. Neuromuscul Disord, 2024. 35: p. 1-7.
9. Serra, L., et al., “I Know that You Know that I Know”: Neural Substrates Associated with Social Cognition Deficits in DM1 Patients. PLoS One, 2016. 11(6): p. e0156901.
10. Cup, E.H., et al., Living with myotonic dystrophy; what can be learned from couples? A qualitative study. BMC Neurol, 2011. 11: p. 86.
PhD from the University of Extremadura and specialized in research on neurodegenerative diseases and autophagy. Her work focuses on studying the cellular and molecular mechanisms of Parkinson’s disease and myotonic dystrophy type 1, primarily using patient-derived cells to identify therapeutic strategies aimed at improving their quality of life.