Pervasive disintegrative disorder: are Rett syndrome and Heller dementia infantilis subtypes?

Children with developmental regression and emerging symptoms of autism have been given a variety of classifications. The authors compare two boys with Heller dementia with six girls with Rett syndrome. They all differed from children with classic autism in that they had normal prenatal and perinatal periods, followed by marked developmental regression, after which they acquired few or no skills. The boys differed from the girls in terms of estimated prevalence, age at onset, stereotypic breathing patterns, midline hand stereotypies, hand and gait apraxia and speech development. It is suggested that these children should be distinguished from those with classic autism, and should be classified as 'pervasive disintegrative disorder, Heller type' and 'pervasive disintegrative disorder, Rett type'.