Belated diagnosis of congenital myotonic dystrophy in a boy with cerebral palsy

We report a boy affected by both congenital myotonic dystrophy (CDM) and cerebral palsy (CP). He was born preterm and suffered from recurrent respiratory distress and respiratory tract infections. He was diagnosed with spastic diplegic CP. During the follow-up, long faces that lacked expression with a drooping mouth, of him and his mother, led to a detailed diagnostic evaluation. His electrodiagnostic testing demonstrated myotonic discharges. Molecular genetic tests revealed that the boy had 1240 CTG repeats and that his mother had 220 repeats, which confirmed the diagnosis of maternally transmitted CDM. Considering the increased obstetric risk of myotonic dystrophy (DM1), children of mothers with DM1 are susceptible to develop disorders such as CP. Clinical suspicion of comorbid CDM should be raised in children with CP who show features suggestive of DM1.