Rapid progressive subacute sclerosing panencephalitis in a 2-year-old child with congenital athyreosis.

We present the unique case of a 2-year-old girl with congenital athyreosis who acquired primary measles virus infection at the age of 18 months, coincidentally with an Epstein-Barr virus infection. First neurologic symptoms of subacute sclerosing panencephalitis appeared 5 months later, and the girl died within 6 months after a rapid progressive illness. Factors possibly predisposing to this extraordinary disease course-primary measles virus infection at an early age and lack of evidence for immunodeficiency-are discussed.