Riga-Fede disease associated with postanoxic encephalopathy and trisomy 21: a proposed classification.

We present a new instance of Riga-Fede disease in a 2-year-old boy with Down syndrome and postanoxic encephalopathy. We propose a classification of the disease, as either "precocious," associated with natal or neonatal teeth or "late-onset," associated with neurologic disease.