This longitudinal study was designed to investigate trajectories of nonverbal cognitive ability in adolescents with fragile X syndrome with respect to the relative influence of fragile X mental retardation protein (FMRP), autism symptom severity, and environmental factors on visualization and fluid reasoning abilities. Males and females with fragile X syndrome (N = 53; ages 10-16 years) were evaluated with the Leiter-R at up to four annual assessments. On average, IQ declined with age. FMRP levels predicted change in fluid reasoning, but not in visualization. The role of FMRP in the neural development that underlies the fragile X syndrome cognitive phenotype is discussed.
Bibliographical noteFunding Information:
This research was supported by NIH grants R01 HD024356 and P30 HD003352 to Leonard Abbeduto and the Waisman Center, respectively, in addition to NIH F31 DC010959 awarded to the first author. Correspondence should be addressed to Sara T. Kover, Ph.D., Waisman Center, 1500 Highland Avenue, Room 475, Madison, WI 53705. E-mail: email@example.com