Effect of the Fragile X Status Categories and the Fragile X Mental Retardation Protein Levels on Executive Functioning in Males and Females with Fragile X

Danuta Z. Loesch, Quang M. Bui, Emma Butler, Richard M. Huggins, Jim Grigsby, Jennifer Epstein, Annette K. Taylor, Randi J Hagerman

Research output: Contribution to journalArticle

91 Scopus citations


The effects of a fragile X disorder on executive function impairment were assessed in 144 extended families, which included individuals with fragile X premutation and full mutation and their relatives without fragile X. A modification of the maximum-likelihood estimators for pedigree data, as well as ordinal logistic regression, were used in data analysis. The most outstanding deficit, occurring especially in males, involved impaired capacity to use an intention to regulate purposeful behavior. This deficit occurred independently of general cognitive impairment but was related to depletion of fragile X mental retardation 1 gene protein product. The other executive function deficits were accounted for by the general cognitive impairment. Possible mechanisms of the effect of fragile X premutation on impairments of executive functioning are considered.

Original languageEnglish (US)
Pages (from-to)646-657
Number of pages12
Issue number4
StatePublished - Oct 2003


ASJC Scopus subject areas

  • Biological Psychiatry
  • Neuropsychology and Physiological Psychology

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