In this article, we describe the language and communication problems of individuals with fragile X syndrome (FXS). FXS is a common genetic disorder resulting from a single-gene mutation on the X chromosome. It is associated with a wide spectrum of physical, behavioral, cognitive, and language problems. Males are typically more severely affected than females, with the vast majority of males having mental retardation. Language and communication are negatively affected by problems in oral-motor structure and function and by conductive hearing loss associated with recurrent otitis media. Speech problems of males with FXS include variability in rate and stuttering-like repetition of sounds. The pattern of speech problems displayed by males is unique to FXS and may reflect a form of developmental dyspraxia. Lexical development is serious delayed in males with FXS. It is less clear, however, whether lexical development keeps pace with achievements in cognitive development and whether receptive and expressive vocabularies are equally impaired. Morphosyntactic development is delayed in males with FXS, with receptive morphosyntax being mental-age-appropriate. It is less clear whether expressive morphosyntactic keeps pace with mental age in affected males. Communication problems are characteristic of both males and females and include features that are syndrome-specific. Most notable among the features displayed by males with FXS is perseveration on a word, phrase, or topic in conversation. Several hypotheses have been advanced to explain this perseveration, but the most promising focus is on hyperarousal and frontal-lobe-executive function deficits. Females with FXS display a run-on, disorganized, and tangential style of conversation that may result from their welldocumented frontal-lobe-executive function deficits. Language and communication intervention for affected individuals requires coordination of medical and behavioral approaches, with the involvement of professionals from several disciplines. Future research must focus on females, on language problems suggested by clinical experience, and on connections between language and communication problems and problems at the neurological and molecular genetic levels.
1997 Wiley-Liss, Inc.