title: Mental status of females with an FMR1 gene full mutation.
abstract: The cloning of the FMR1 gene enables molecular diagnosis in patients and in carriers (male and female) of this X-linked mental retardation disorder. Unlike most X-linked disorders, a considerable proportion of the female carriers of a full mutation of the FMR1 gene is affected. In this study, the intelligence quotients (IQs) were ascertained by the Wechsler Adult Intelligence Scale in 33 adult females with a full mutation, with 28 first-degree adult female relatives (mainly sisters) without a full mutation as controls. Seventy-one percent of the females with a full mutation had IQ scores below 85. In paired analysis, no significant correlation could be detected between the IQs of the females with a full mutation and those of their first-degree female relatives, reflecting a dominant effect of the FMR1 gene full mutation in the mental development of females. Considering females with a full mutation only, we observed a significant relation between the proportion of normal FMR1 alleles on the active X chromosome and IQ. We present a model to explain this relationship.
authors.affiliation: Department of Clinical Genetics, University Hospital Dijkzigt, Rotterdam, The Netherlands.
authors.forename: B B
authors.initials: BB
authors.lastname: de Vries
authors.forename: A M
authors.initials: AM
authors.lastname: Wiegers
authors.forename: A P
authors.initials: AP
authors.lastname: Smits
authors.forename: S
authors.initials: S
authors.lastname: Mohkamsing
authors.forename: H J
authors.initials: HJ
authors.lastname: Duivenvoorden
authors.forename: J P
authors.initials: JP
authors.lastname: Fryns
authors.forename: L M
authors.initials: LM
authors.lastname: Curfs
authors.forename: D J
authors.initials: DJ
authors.lastname: Halley
authors.forename: B A
authors.initials: BA
authors.lastname: Oostra
authors.forename: A M
authors.initials: AM
authors.lastname: van den Ouweland
authors.forename: M F
authors.initials: MF
authors.lastname: Niermeijer
mesh_terms: D000328:Adult; D000368:Aged; D004247:DNA / Q000032:analysis; D005260:Female; D005600:Fragile X Syndrome / Q000235:genetics / Q000523:psychology*; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D008957:Models, Genetic; D009154:Mutation
chemical_list: D004247:DNA