Candidate genes personality DRD4 Flashcards Preview

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Flashcards in Candidate genes personality DRD4 Deck (7)
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1
Q

Link between DRD4.7 and promiscuity

  • Questionnaires, US students.
  • Those with 7 or more repeats had almost 2x greater promiscuity rate and were more likely to be unfaithful during a committed relationship
A

Garcia et al 2010

2
Q

Link between DRD4 polymorphism, sexual desire, arousal and function.

  • NB subjects were volunteers: recruited by an advertisement on an internet site for subjects who had already given DNA in previous studies. However efforts were made to keep process anonymous and avoid direct contact: recruited by phone, gave no details apart from an identifying code, online questionnaire.
  • Used online questionnaire on sexual desire, arousal and function.
  • 5 polymorphisms were genotyped in 148 subjects.
  • Men and women differed significantly on desire and function scores.
  • DRD4 exon 3 most common D4.4 repeat was negatively associated with desire. D4.7 carriers showed higher sexual function/desire than D4.4
  • C-521 ‘T’ alleles also showed higher desire scores,
A

Zion et al 2006

3
Q

Interaction with high number of friends leads to liberal politics?

  • 2574 subjects. Comparison within families to avoid stratification
  • Those with DRD4-7R and a large number of friends are more likely to be liberal in their policies.
A

Settle et al 2010

4
Q

Effects in different directions for men and women for cognitive empathy (‘I try to look at everybody’s side of the disagreement before I make a decision’)

  • DRD4-7R associated with higher cognitive empathy in females, but lower cognitive empathy in males.
A

Uzefovsky et al 2014

5
Q

124 subjects

7-repeat allele was significantly associated with Cloniger’s trait of ‘Novelty Seeking’

NB results have not always been replicated

A

Ebstein et al 1996

6
Q

DRD4 gene may be associated with measures of novelty seeking and impulsivity (but not extraversion). The association of C-521T variant with these measures, if genuine, may account for up to 3% of phenotypic variance.

Meta-analysis of studies of the association between DRD4 gene variable number of tandem repeats (VNTR) and C-521T polymoprphisms and human approach-related personality traits, including novelty seeking, extraversion and impulsivity.

  • Adult samples from nonpsychiatric populations.
  • Then extended on this literature by trying to confirm any evidence of association in a replication sample (n-309) selected for extreme scores on the extraversion subscale of the Eysenck Pesrsonality Questionnaire from a large (n~40000) population based samples)

Results:

  • Initial meta-analysis supported association of DRD4 C-521T polymorphism but not the VNTR polymorphism, with approach-related traits.
  • Conclusion was qualified by evidence of signidicant publication bias & failure to detect assocaiation in a replication sample comprising individuals at the extremes of the trait distribution.
  • Association of C-521T polymorphism was robust to inclusion of these new data, but revised meta-analysis indicated that association was present for novelty seeking and impulsivity but not extraversion.
A

Munafo et al 2008

7
Q

In unselected wild caught birds, SNP830 polymorphism correlates with novelty-seeking.

  • Studies wild-caught great tits, a species in which selective breeding has previously shown that novelty-seeking has a significant genetic basis. Measured (a) exploration in a novel environment and (b) birds reaction to 2 different novel objects placed in home cage
  • Composite score for (a) and (b) was related to an SNP at position 830 of the DNDR4 nucleotide sequences.
  • BUT NB awkward issue with this polymorphism: substitution of C to T is ‘synonymous’ as both cases encode alanine. Possible alternative differencially affect transcription, splicing or the stability of RNA? Or might be in linkage disequilibrium with another polymorphism nearby.
A

Fidler et al 2007