Pons tumour behind a phenotypic Rett syndrome presentation.

We describe a girl with a brain-stem tumour and symptoms very similar to those of Rett syndrome (RS). Her early history was uneventful and development was normal (except for hypotonia). At the age of 6 months her development slowed. Subsequently, deterioration occurred and the features characteristic of RS were seen: loss of purposeful hand use, stereotypic hand movements, impaired social contact, decelerated head growth, and ataxia. Cerebral CT at the age of 3 years and 4 months revealed a tumour in the region of the pons and hydrocephalus. We suggest that a pons/midbrain tumour appearing at an early age may affect the developing CNS and cause symptoms similar to those of RS. A possible causal connection between midbrain pathology and RS is supported by this case.