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Mapping nonverbal IQ in young boys with fragile X syndrome.

Publication ,  Journal Article
Skinner, M; Hooper, S; Hatton, DD; Roberts, J; Mirrett, P; Schaaf, J; Sullivan, K; Wheeler, A; Bailey, DB
Published in: Am J Med Genet A
January 1, 2005

This study examines the developmental changes in nonverbal intellectual functioning evident in males with fragile X syndrome (FXS) measured by the Leiter International Performance Scales-Revised (Leiter-R). The Leiter-R provides both IQ scores and associated growth scores which permit the examination of both age-based IQ scores and overall intellectual growth. Participants were 45 males with full mutation FXS and ranged in age from 4.0 to 13.8 years. Each child was assessed annually using the Leiter-R as part of a larger longitudinal battery for an average of 3.5 assessments per child and a range of 2-6 assessments, representing a total of 156 assessment occasions. Longitudinal analyzes of Leiter scores consisted primarily of hierarchical linear modeling, with the impact of chronological age, maternal education, fragile X mental retardation 1 protein (FMRP), autistic behaviors also being assessed. Findings revealed a significant linear decline in nonverbal IQ scores, with no effects of maternal education, autistic behaviors, or FMRP on mean level or rate of change in IQ scores over time. The decline slowed significantly around 8 years of age, but scores continued to decline into the 12th year of age. In contrast, a significant linear increase was observed in Leiter-R growth scores, which was negatively influenced by autistic behaviors. The rate of increase did not change over time, and neither mean level nor rate of increase was influenced by maternal education or FMRP levels. These findings suggest that declines in IQ are the result of steady, but suboptimal intellectual growth, rather than a true deterioration in overall intellectual functioning.

Duke Scholars

Published In

Am J Med Genet A

DOI

ISSN

1552-4825

Publication Date

January 1, 2005

Volume

132A

Issue

1

Start / End Page

25 / 32

Location

United States

Related Subject Headings

  • RNA-Binding Proteins
  • Nerve Tissue Proteins
  • Mutation
  • Male
  • Longitudinal Studies
  • Intelligence Tests
  • Intelligence
  • Immunohistochemistry
  • Humans
  • Fragile X Syndrome
 

Citation

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Chicago
ICMJE
MLA
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Skinner, M., Hooper, S., Hatton, D. D., Roberts, J., Mirrett, P., Schaaf, J., … Bailey, D. B. (2005). Mapping nonverbal IQ in young boys with fragile X syndrome. Am J Med Genet A, 132A(1), 25–32. https://doi.org/10.1002/ajmg.a.30353
Skinner, Martie, Stephen Hooper, Deborah D. Hatton, Jane Roberts, Penny Mirrett, Jennifer Schaaf, Kelly Sullivan, Anne Wheeler, and Donald B. Bailey. “Mapping nonverbal IQ in young boys with fragile X syndrome.Am J Med Genet A 132A, no. 1 (January 1, 2005): 25–32. https://doi.org/10.1002/ajmg.a.30353.
Skinner M, Hooper S, Hatton DD, Roberts J, Mirrett P, Schaaf J, et al. Mapping nonverbal IQ in young boys with fragile X syndrome. Am J Med Genet A. 2005 Jan 1;132A(1):25–32.
Skinner, Martie, et al. “Mapping nonverbal IQ in young boys with fragile X syndrome.Am J Med Genet A, vol. 132A, no. 1, Jan. 2005, pp. 25–32. Pubmed, doi:10.1002/ajmg.a.30353.
Skinner M, Hooper S, Hatton DD, Roberts J, Mirrett P, Schaaf J, Sullivan K, Wheeler A, Bailey DB. Mapping nonverbal IQ in young boys with fragile X syndrome. Am J Med Genet A. 2005 Jan 1;132A(1):25–32.
Journal cover image

Published In

Am J Med Genet A

DOI

ISSN

1552-4825

Publication Date

January 1, 2005

Volume

132A

Issue

1

Start / End Page

25 / 32

Location

United States

Related Subject Headings

  • RNA-Binding Proteins
  • Nerve Tissue Proteins
  • Mutation
  • Male
  • Longitudinal Studies
  • Intelligence Tests
  • Intelligence
  • Immunohistochemistry
  • Humans
  • Fragile X Syndrome