Cognitive and molecular aspects of fragile X

The relationships among parental origin of the fragile X gene, gene structure, and specific cognitive deficits were evaluated in nonretarded adult female fragile X carriers to determine whether: (1) origin influences gene structure and cognitive function, (2) mild cognitive impairments are associated with altered gene structure, and (3) specific cognitive domains are affected. Results indicated that 56% of women with maternally inherited, but none with paternally inherited, fragile X showed large genomic structural alterations and selective deficits on measures of visual attention. Thus, molecular status of the fragile X gene appears to be linked to parental origin and may selectively affect specific cognitive skills.