Linkage Disequilibrium Analysis of G-olfα (GNAL) in Bipolar Affective Disorder

S. J. Tsiouris, T. S. Breschel, J. Xu, M. McInns, F. J. McMahon

Research output: Contribution to journalArticle


This study examines G-olfα as a possible candidate gene for susceptibility to bipolar affective disorder (BPAD) using the Transmission Disequilibrium Test (TDT). G-olfα, which encodes a subunit of a G-protein involved in intracellular signaling, maps within a region of chromosome 18 that has been implicated by two different linkage studies as a potential site of BPAD susceptibility loci. The expression pattern of G-olfα in the brain, its coupling to dopamine receptors, and the effects of lithium salts on G-proteins all support G-olfα as a candidate gene for BPAD. Our study population consisted of 106 probands and sibs with bipolar I disorder, with a median age-at-onset of 21.5 years ascertained from the United States. There was no evidence of linkage disequilibrium between BPAD and any of the observed G-olfα alleles in our sample. Division of families based on sex of the transmitting parent did not significantly change the results. This sample had good power (78%) to detect linkage disequilibrium with alleles conferring a relative risk equal to that estimated for the putative 18p locus (2.58). Our results do not support a major role for G-olfα as a susceptibility locus for BPAD in a substantial portion of our sample. Other genes lying near G-olfα within the linked region on chromosome 18 cannot be excluded by our data. This study illustrates the use of the TDT in evaluating candidate genes within linked chromosome regions.

Original languageEnglish (US)
Pages (from-to)491-494
Number of pages4
JournalAmerican Journal of Medical Genetics - Seminars in Medical Genetics
Issue number5
Publication statusPublished - Sep 20 1996



  • Bipolar I
  • G-proteins
  • Genetics
  • Mood disorder
  • Transmission Disequilibrium Test (TDT)

ASJC Scopus subject areas

  • Genetics(clinical)
  • Neuroscience(all)
  • Neuropsychology and Physiological Psychology

Cite this

Tsiouris, S. J., Breschel, T. S., Xu, J., McInns, M., & McMahon, F. J. (1996). Linkage Disequilibrium Analysis of G-olfα (GNAL) in Bipolar Affective Disorder. American Journal of Medical Genetics - Seminars in Medical Genetics, 67(5), 491-494.