The Development of Morphosyntax in Fragile X Syndrome

Abstract

An objective of research in developmental disabilities is the comparison of language phenotypes. Disorders with similar symptomology, such as autism and fragile X syndrome (FXS) are of particular interest. One area of inquiry within language development is morphosyntax (the interplay between grammatical morphology and syntactic structure). The purpose of this study was to examine morphosyntax in a group of children with FXS, while examining the impact of autism on FXS. Differences in gender were also examined. Twenty-six boys and 7 girls between 7-16 years participated. Children completed standardized tests and a language sample. The examiner completed an autism rating scale. The data indicated that boys with FXS do have a deficit in morphosyntax, relative to language comprehension. The presence of autism had a negative impact. Some of the females in this study had low nonverbal IQ, and receptive language scores. Females had low percentage correct for irregular past tense verbs.