[Psycholinguistic aspects of fragile X chromosome syndrome].

Fragile X syndrome is the first cause of hereditary mental retardation. Numerous studies have approached the physical and behavioural phenotypes. This paper will review the main characteristics of speech and language in children with fragile X syndrome. Boys show a late language acquisition, differing comprehension and expression levels, good semantic and syntax acquisition, and speech problems: perseverance, unequal rythm and pragmatic difficulties: respect for conversation turns, speech maintenance, active avoidance of visual contact. A lesser degree of speech problems is described for FXS girls and the influence of social anxiety and hypersensitivity to social and sensorial stimuli on language production is discussed.