Language development and fragile X syndrome: profiles, syndrome-specificity, and within-syndrome differences.
Fragile X syndrome (FXS) is the leading inherited cause of mental retardation. In this article, we review what is known about the language and related problems of individuals with FXS. In doing so, we focus on the syndrome-specific features of the language phenotype and on the organismic (i.e., genetic and individual neurocognitive and behavioral) and environmental factors associated with within-syndrome variation in the phenotype. We also briefly review those aspects of the behavioral phenotype of FXS that are relevant for understanding syndrome-specific features of, and within-syndrome variability in, language. The review includes summaries of research on the prelinguistic foundations for language development and on each of the major components of language (i.e., vocabulary, morphosyntax, and pragmatics). Throughout the review, we point out implications of existing research for intervention as well as directions for future research.
Abbeduto
Leonard
L
Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA. abbeduto@waisman.wisc.edu
Brady
Nancy
N
Kover
Sara T
ST
D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics; D005600:Fragile X Syndrome / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D008607:Intellectual Disability / Q000453:epidemiology; D007805:Language Development Disorders / Q000145:classification* / Q000453:epidemiology*; D017354:Point Mutation / Q000235:genetics; D015995:Prevalence; D012931:Social Environment; D014706:Verbal Learning; D014825:Vocabulary
D051860:Fragile X Messenger Ribonucleoprotein 1; C497683:FMR1 protein, human