Myotonic dystrophy type 1 has distal weakness, with myotonia prominent in the hands; type 2 has proximal muscle weakness (also called PROMM or proximal myotonic myopathy). The signs and symptoms of myotonic dystrophy typically manifest in the third or fourth decade, although they can occur at any age.
Congenital myotonic dystrophy can occur in neonates born to affected mothers. These children have a severe phenotype with prominent weakness, hypotonia, skeletal abnormalities, feeding difficulties, and respiratory distress at birth.
G71.11 – Myotonic muscular dystrophy
77956009 – Steinert myotonic dystrophy syndrome
Differential Diagnosis & Pitfalls