This is a copy of the article from J of Pediatrics MArch 16, 2013

The myotonic dystrophies have been called the most “diverse diseases known in medicine,”¹ and in many respects, the broad spectrum of manifestations observed in myotonic dystrophy type 1 (DM1) are most evident when an undiagnosed and mildly affected mother gives birth to a severely affected child. DM1 results from an unstable trinucleotide repeat expansion (CTG) in the dystrophia myotonica-protein kinase gene (DMPK), located on chromosome 19q13.3.², ³, ⁴

Congenital myotonic dystrophy (CDM) often presents as the index case in a family affected by DM1, and the diagnosis is made within the first few hours and days after birth. Neonatal symptoms can be life- threatening and include respiratory failure, feeding difficulties, hypotonia, and muscle weakness.⁵, ⁶, ⁷ The childhood years may bring marked dysarthria, intellectual impairment, and features of autistic spectrum disorders.⁸, ⁹, ¹⁰ Mothers of patients with CDM often have a diagnosis of DM1 established when their child is diagnosed. These mothers often have mild facial or distal muscle weakness, mild myotonia, and other multisystem manifestations, such as cataracts. Both diagnoses (CDM and adult DM1) can usher in a whirlwind of short- and long-term medical, psychosocial, and economic complications and decisions. Unfortunately, to date, limited empirical information is available to inform care providers, patients, and their family members about the prevalence and natural history of CDM.

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