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    This article has been cited by the following publications. This list is generated based on data provided by CrossRef.

    Arguedas, Deborah and Batchelor, Jennifer 2009. 18q Deletion syndrome: A neuropsychological case study. Neurocase, Vol. 15, Issue. 2, p. 101.

    Zavala, Juan Ramirez, Mercedes Medina, Rolando Heard, Patricia Carter, Erika Crandall, AnaLisa Hale, Daniel Cody, Jannine and Escamilla, Michael 2009. Psychiatric syndromes in individuals with chromosome 18 abnormalities. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics, Vol. 9999B, p. n/a.

    Feenstra, Ilse Vissers, Lisenka E.L.M. Orsel, Mirjam van Kessel, Ad Geurts Brunner, Han G. Veltman, Joris A. and van Ravenswaaij-Arts, Conny M.A. 2007. Genotype–phenotype mapping of chromosome 18q deletions by high-resolution array CGH: An update of the phenotypic map. American Journal of Medical Genetics Part A, Vol. 143A, Issue. 16, p. 1858.

    Netzer, C. Helmstaedter, C. Ehrbrecht, A. Engels, H. Schwanitz, G. Urbach, H. Schroder, R. Weber, R. G. and Kornblum, C. 2006. Global brain dysmyelination with above-average verbal skills in 18q - syndrome with a 17 Mb terminal deletion. Acta Neurologica Scandinavica, Vol. 114, Issue. 2, p. 133.

  • Journal of the International Neuropsychological Society, Volume 11, Issue 5
  • September 2005, pp. 584-590

Cognitive ability predicts degree of genetic abnormality in participants with 18q deletions

  • DOI:
  • Published online: 01 August 2005

One of the most common chromosomal deletions is a loss of genetic material from the long arm of chromosome 18. Most individuals with this condition exhibit mental retardation (68%), yet previous attempts to link cognitive status to deletion size have not shown an association, possibly because cases with additional genetic abnormalities were included. We studied 46 participants ranging from 3 to 35 years of age who had a pure genetic abnormality by excluding those with mosaicism or complex genetic rearrangements. Our patients had terminal deletions ranging from a proximal breakpoint at 18q21.1 (greater genetic abnormality, larger deletion size) to a more distal breakpoint at 18q23 characterized with molecular genetic techniques. Cognitive ability, assessed with the age-appropriate measure (Bayley, 1993, Differential Ability Scale, Wechsler Scales), ranged from IQ = 49 to 113, with a predominance of mild and moderate mental retardation. Using multivariate regression, deletion size breakpoint rank order was predicted by cognitive ability, age, and adaptive behavior (Vineland Adaptive Behavior Scales), accounting for 36% of the variance in deletion size. However, lower cognitive ability (beta = .34, p = .032) and younger age (beta = .296, p = .024) predicted a larger deletion size, but adaptive behavior (beta = .225, p = .15) did not. An additional multivariate regression showed that cognitive ability and age together accounted for 33% of the variance in deletion size, whereas univariate regression showed that cognitive ability accounted for 26% of the variance and age accounted for 11% of the variance. These findings suggest that degree of cognitive impairment is associated with genetic abnormality when a large sample of individuals with “pure” deletions of genetic material from chromosome 18 is examined. (JINS, 2005, 11, 584–590.)

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Reprint requests to: Margaret Semrud-Clikeman Ph.D., Department of Educational Psychology, D5800, 1 University Station, Austin, TX 78712. E-mail:
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Journal of the International Neuropsychological Society
  • ISSN: 1355-6177
  • EISSN: 1469-7661
  • URL: /core/journals/journal-of-the-international-neuropsychological-society
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