Rett syndrome symptomatology of institutionalized adults with mental retardation: comparison of males and females.

Institutionalized adults with mental retardation (N = 297) were surveyed to determine the prevalence of symptoms of Rett syndrome. No symptom of the syndrome occurred more frequently in males than females. When symptoms were analyzed in clusters (e.g., severe mental retardation, no prenatal complications, walked before 15 months, and wide-based gait), no single cluster of symptoms appeared to differentiate males from females. However, as individuals, only females were found to meet the necessary criteria for a diagnosis of Rett syndrome. Symptoms were seen with equal frequency in this population and no one or two symptoms differentiated patients with and without Rett syndrome.