[A case of congenital myotonic dystrophy with infantile autism]

An 11-year-old girl with congenital myotonic dystrophy and infantile autism was reported. Her mother also suffered from typical myotonic dystrophy. Since her birth, the patient had been floppy, and showed bilateral talipes equinus at 1 year of age. Her subsequent psychomotor and speech development has been retarded. She showed autistic behavior and persistence to the sameness before 2 years old. She was admitted to Sawarabien at the age of 10 years. She could not talk anything but could understand simple, oral messages. Although she had severe degree of mental retardation, her ability for matching figures was relatively well reserved. Her autism was so manifest that it could not be explained by the degree of mental retardation. Neurological examinations revealed that she had facial diplegia, inverted V-shaped mouth, high-arched palate, talipes equinus, percussion myotonia of the tongue, generalized muscular atrophy and weakness, lordosis, areflexia, and congenital cataracta. The serum CPK was slightly elevated. EMG showed a myopathic pattern but did not show any myotonic discharge yet. The brachioradial muscle was biopsied and examined by light- and electron-microscopy. It mainly showed mild varieties of muscle fiber diameter and internal nuclei. Ultrastructurally, irregularly indented central nuclei and perinuclear degeneration of myofibrils associated with secondary lysosomes, lipid droplets and glycogen granules were revealed. Ventricular dilatation and some dysfunction of the brain were also revealed by CT scan and EEG respectively. The present case suggests that congenital myotonic dystrophy can be added into the disease group associated with infantile autism.