Association testing of the positional and functional candidate gene SLC1A1/EAAC1 in early-onset obsessive-compulsive disorder

Arch Gen Psychiatry. 2006 Jul;63(7):778-85. doi: 10.1001/archpsyc.63.7.778.


Context: The first 2 independent linkage studies for obsessive-compulsive disorder (OCD) identified a region on 9p24 with suggestive evidence for linkage. The glutamate transporter gene solute carrier family 1, member 1 (SLC1A1) is a promising functional candidate in this region because altered glutamatergic concentrations have been found in the striatum and anterior cingulate in neuroimaging studies of pediatric OCD.

Objective: To determine whether genotypes at polymorphisms in the SLC1A1 gene region are associated with early-onset OCD.

Design: Family-based analysis of association using the transmission disequilibrium test, confirmed using the family-based association test.

Setting: Anxiety disorders program in an academic medical center.

Participants: Seventy-one probands with DSM-III-R or DSM-IV OCD and their parents.

Methods: Nine single nucleotide polymorphisms spaced throughout the SLC1A1 gene region were genotyped.

Results: Significant association was detected at rs3780412 (P = .04) and rs301430 (P = .03), 2 common adjacent single nucleotide polymorphisms in the 3' region of SLC1A1. Analysis by sex revealed that association at rs3780412 was limited to male probands (P = .002). Significant association was also detected for the T/C haplotype at rs301430-rs301979 (P = .03), the only haplotype block identified among the 9 single nucleotide polymorphisms. Analysis by sex also revealed that the haplotype association was limited to male probands (P = .003). A deletion in the 3' flanking region of SLC1A1 was also detected that imperfectly segregated with OCD in a large, multigenerational family with multiple affected individuals.

Conclusions: The 3' region of SLC1A1 may contain a susceptibility allele for early-onset OCD, with differential effects in males and females. The results also provide further support for the involvement of a glutamatergic dysfunction in the pathogenesis of early-onset OCD.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Age of Onset
  • Aged
  • Child
  • Chromosome Mapping
  • Excitatory Amino Acid Transporter 3 / genetics*
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease / genetics
  • Genotype
  • Haplotypes / genetics
  • Humans
  • Linkage Disequilibrium / genetics
  • Male
  • Middle Aged
  • Obsessive-Compulsive Disorder / diagnosis
  • Obsessive-Compulsive Disorder / genetics*
  • Pedigree
  • Polymorphism, Single Nucleotide / genetics
  • Sex Factors


  • Excitatory Amino Acid Transporter 3
  • SLC1A1 protein, human