RE/PMT may be applied clinically with the expectation of medium-size effects on the child's rate of intentional communication acts after 6 months of intervention. The approach warrants further investigation with modifications, such as delivery at higher intensity levels.

Purpose: This study examined the expressive language abilities of a subset of highly verbally expressive adolescents and young adults with Down syndrome (DS) and those with fragile X syndrome (FXS) for evidence of syndrome-related differences. FXS gender differences were also examined in an exploratory fashion. Method: We evaluated 24 adolescents and young adults with DS, 17 of those with FXS, and 21 children with typical development (TD), with the groups matched on nonverbal mental age. Language ability was examined using the Oral and Written Language Scales (OWLS; Carrow-Woolfolk, 1995) and Developmental Sentence Scoring (DSS; Lee, 1974) scores derived from an oral narrative language sample. Results: Study analyses revealed the following group differences: the FXS group outperformed the DS and TD groups on the OWLS measure; the TD group outperformed both other groups on some of the DSS measures; the FXS group outperformed the DS group on the DSS Sentence Point measure; and females with FXS outperformed males with FXS on several measures. Conclusions: The study results contribute to the ongoing construction of the language phenotypes of individuals with DS and individuals with FXS and support the conclusion that there are quantitative rather than qualitative differences in their expressive language profiles.

Fragile X syndrome (FXS) is the leading inherited cause of intellectual disability. The syndrome is caused by a single gene mutation on the X chromosome. Although individual differences are large, most individuals with FXS display weaknesses across all language and literacy domains compared to peers of the same chronological age with typical cognitive and language development. Expressive, receptive, and pragmatic language abilities as well as literacy skills are similar to those of younger, typically developing peers at similar cognitive and language developmental levels, although there are areas in which impairments exceed developmental-level expectations. One area of special impairment is the higher occurrence of repetition in the language of individuals with FXS compared to developmentally matched peers. In this paper, we review the behavioral, language, and literacy characteristics of individuals with FXS and discuss potential clinical implications.

Although they often have significant difficulties in other areas, most children with specific language impairment (SLI) have special difficulties with the understanding and use of grammar. Therefore, most of these children will require an intervention program that targets comprehension or production of grammatical form. Language interventionists are faced with the difficult task of developing comprehensive intervention programs that address the children's grammatical deficits while remaining sensitive to their other existing and predictable social, behavioral, and academic problems. The purpose of this article is to present and justify 10 principles that we regard as essential for planning adequate interventions for children with language-learning problems. These principles are relevant for all children with problems in the use of grammar, but they are especially appropriate for 3- to 8-year-old children with SLI. Although all of our examples are from English, the principles we have chosen are sufficiently broad to cut across many linguistic and cultural boundaries.