NEUROBEHAVIORAL CHARACTERISTICS OF CGG AMPLIFICATION STATUS IN FRAGILE-X FEMALES

Neurobehavioral correlates of CGG amplification were studied in 17 nonretarded adult female carriers of fragile X syndrome. The results revealed a significant relationship between IQ and the number of CGG repeats in the 5' untranslated region of the FMR1 gene. Women with a full mutation (>200 CGG repeats) scored below average in IQ, visual-spatial perception, visual-spatial organization, and executive function. There were no differences in hue motor dexterity or memory as a function of CGG amplification status. A history of major depressive disorder was identified in 71% of the sample, but incidence of depression was not associated with the degree of CGG amplification. Schizotypal features were noted in 18%. No intellectual or neuropsychological deficit was found in women with a premutation (<200 CGG repeats). Decrements in IQ, visual-spatial perception, and executive function appear to arise as a consequence of the CGG amplification. (C) 1994 Wiley-Liss, Inc,