How DM Affects Your Body

Myotonic dystrophy (DM) is a multisystemic disorder that can affect all age groups. Because of the range of systems affected, management requires a more expansive approach than most disorders and care is best provided by a coordinated, multidisciplinary team.

Cardiovascular System

  • Heart rhythm problems (arrhythmias)
  • Enlarged heart muscle
  • Low blood pressure
  • Sudden death


  • Difficulty with thinking and problem solving
  • Emotional and behavior problems
  • Excessive daytime sleepiness
  • Nerve damage in feet and hands

Reproductive System

  • Small testes, low sperm count, low testosterone
  • Higher risk of miscarriage and stillbirth; early menopause
  • Problems with pregnancy and delivery
  • Newborn complications


  • Cataracts
  • Damage to the retina
  • Drooping eyelids (ptosis)



Immune System

  • Lower levels of antibodies in bloodstream (hypogammaglobulinemia)
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  • Higher risk of benign skin tumor (pilomatrixoma)

Respiratory System

  • Breathing problems in newborns
  • Frequent lung infections
  • Aspiration of food or fluids into airways
  • Inability to breathe in enough oxygen
  • Sleep apnea

Gastrointestinal System

  • Difficulty swallowing
  • Pain and bloating after meals
  • Constipation, diarrhea, irritable bowel syndrome, gastrointestinal reflux
  • Gallstones
  • Enlarged colon


  • Insulin resistance
  • Premature frontal balding in men


  • Muscle weakness (myopathy)
  • Muscle stiffness and trouble relaxing a muscle (myotonia)
  • Muscle wasting that gets worse over time (atrophy)
  • Severe muscle weakness and delayed development in newborns and infants


  • Inherited disease, autosomal-dominant mutation
  • 50% chance of passing mutated gene to each child
  • More severe with each generation ("anticipation")

Congenital and Juvenile-Onset

  • Earlier onset of symptoms, often more severe symptoms than adult-onset
  • Congenital form can present potentially life-threatening issues at birth
  • Juvenile/childhood-onset form typically first presents with intellectual disability and/or learning disabilities
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