The preserved speech variant: a subgroup of the Rett complex: a clinical report of 30 cases

Thirty girls and young women, 6 from Sweden and 24 from Italy, are described in this paper. They ranged in age from 5 through 28 years. All but one of the cases met full symptom criteria for DSM-IV autistic disorder. However, they also showed many features of classic Rett syndrome (RS) as outlined by the Rett syndrome Diagnostic Criteria Work Group. All met the required 3 out of 6 main criteria and 47% also met both these and the required 5 out of 11 supportive criteria for RS variants as outlined by Hagberg. The course of the disorder was more benign than in classic RS, but all the girls were severely functionally impaired. There was familial clustering in a subgroup. It is concluded that these 30 cases represent a syndrome, similar and probably related, to classic RS. It is suggested that there is a spectrum of syndromes ranging from severe cases with classical presentation to considerably milder variants. We propose that, at the present state of knowledge, these conditions might be best categorized as subgroups of the "Rett Complex," in which classical RS and the preserved speech variant may be the most frequent.