Journal of Autism and Developmental Disorders

, Volume 38, Issue 1, pp 184–189

Brief Report: Aggression and Stereotypic Behavior in Males with Fragile X Syndrome—Moderating Secondary Genes in a “Single Gene” Disorder

  • David Hessl
  • Flora Tassone
  • Lisa Cordeiro
  • Kami Koldewyn
  • Carolyn McCormick
  • Cherie Green
  • Jacob Wegelin
  • Jennifer Yuhas
  • Randi J. Hagerman
Brief Report

DOI: 10.1007/s10803-007-0365-5

Cite this article as:
Hessl, D., Tassone, F., Cordeiro, L. et al. J Autism Dev Disord (2008) 38: 184. doi:10.1007/s10803-007-0365-5

Abstract

Although fragile X syndrome (FXS) is a single gene disorder with a well-described phenotype, it is not known why some individuals develop more significant maladaptive behaviors such as aggression or autistic symptoms. Here, we studied two candidate genes known to affect mood and aggression, the serotonin transporter (5-HTTLPR) and monoamine oxidase A (MAOA-VNTR) polymorphisms, in 50 males with FXS ages 8–24 years. Mothers and fathers of participants reported the frequency and severity of aggressive/destructive, self-injurious, and stereotypic behaviors. Polymorphism genotypes were unrelated to age and IQ. Results showed a significant effect of 5-HTTLPR genotype on aggressive/destructive and stereotypic behavior; males with FXS who were homozygous for the high-transcribing long (L/L) genotype had the most aggressive and destructive behavior, and individuals homozygous for the short (S/S) genotype had the least aggression. Those with the L/L genotype also had the highest levels of stereotypic behavior. There was no effect of MAOA-VNTR on behavior; however those with the high-activity, 4-repeat genotype were more likely to be taking SSRI or SNRI medication. This preliminary study prompts consideration of secondary genes that may modify behavioral phenotype expression in neurodevelopmental disorders, even those with a single gene etiology such as FXS.

Keywords

Serotonin transporterMonoamine oxidase APolymorphism5-HTTLPR, MAOAFMR1 geneSelf-injurious behavior

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • David Hessl
    • 1
    • 2
  • Flora Tassone
    • 1
    • 4
  • Lisa Cordeiro
    • 1
  • Kami Koldewyn
    • 1
    • 6
  • Carolyn McCormick
    • 1
  • Cherie Green
    • 1
  • Jacob Wegelin
    • 2
    • 5
  • Jennifer Yuhas
    • 1
  • Randi J. Hagerman
    • 1
    • 3
  1. 1.Medical Investigation of Neurodevelopmental Disorders (MIND) InstituteUniversity of California-Davis, Medical CenterSacramentoUSA
  2. 2.Department of Psychiatry and Behavioral SciencesUniversity of California-Davis, Medical CenterSacramentoUSA
  3. 3.Department of PediatricsUniversity of California-Davis, Medical CenterSacramentoUSA
  4. 4.Department of Biochemistry and Molecular MedicineUniversity of California-Davis, School of MedicineDavisUSA
  5. 5.Division of BiostatisticsUniversity of California-Davis, School of MedicineDavisUSA
  6. 6.Center for NeuroscienceUniversity of California-DavisDavisUSA