Use of monozygotic twins to investigate the relationship between 5HTTLPR genotype, depression and stressful life events: an application of Item Response Theory

Title
Use of monozygotic twins to investigate the relationship between 5HTTLPR genotype, depression and stressful life events: an application of Item Response Theory
Publication Date
2008
Author(s)
Wray, Naomi R
Coventry, William Luya
( author )
OrcID: https://orcid.org/0000-0003-0864-5463
Email: wcovent2@une.edu.au
UNE Id une-id:wcovent2
James, Michael R
Montgomery, Grant W
Eaves, Lindon J
Martin, Nicholas G
Editor
Editor(s): Michael Rutter
Type of document
Book Chapter
Language
en
Entity Type
Publication
Publisher
John Wiley & Sons Ltd
Place of publication
Chichester, United Kingdom
Edition
1
Series
Novartis Foundation symposia
UNE publication id
une:5895
Abstract
We examine the interaction between stressful life events (SLE) and genotypes for the length polymorphism of the serotonin receptor gene (SHTTLPR) on risk of depression. We hypothesize that if the interaction is real, monozygotic twin pairs (MZT) homozygous for the short allele (SS) will have a greater within pair variance In depression measures than MZT homozygous for the long allele (LL), as a reflection of their increased sensitivity to unknown environmental risk factors. Telephone interviews were used to assess symptoms of depression and suicidality on 824 MZT. Rather than using the interview items to calculate sum scores or allocate diagnostic classes we use Item Response Theory to model the contribution of each item to each individual's underlying liability to depression. SLE were also measured on the MZT assessed by mailed questionnaire on average 3.8 years previously, and these were used in follow-up analyses. We find no evidence for significant differences in within pair variance between 5HTTLPR genotypic classes and so can provide no support for interaction between these genotypes and the environment. The use of MZT provides a novel framework for examining genotype X environment interaction in the absence of measures on SLE.
Link
Citation
Genetic Effects on Environmental Vulnerability to Disease, p. 48-67
ISBN
047077780X
9780470777800
Start page
48
End page
67

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