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The Association of the Dopamine D4 Receptor Gene (DRD4) and the Serotonin Transporter Promoter Gene (5‐HTTLPR) with Temperament in 12‐month‐old Infants
Author(s) -
Auerbach Judith G.,
Faroy Michal,
Ebstein Richard,
Kahana Merav,
Levine Joseph
Publication year - 2001
Publication title -
journal of child psychology and psychiatry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.652
H-Index - 211
eISSN - 1469-7610
pISSN - 0021-9630
DOI - 10.1111/1469-7610.00774
Subject(s) - 5 httlpr , serotonin transporter , temperament , psychology , allele , anger , serotonin , genotype , medicine , endocrinology , genetics , receptor , gene , psychiatry , personality , biology , psychoanalysis
This study examined the association between two common polymorphisms, the dopamine D4 receptor (DRD4) gene and the serotonin transporter promoter (5‐HTTLPR) gene and temperament in 61 infants aged 12 months. Twenty‐two infants had a least one copy of the 6–8 repeat DRD4 alleles (L‐DRD4) and 39 had two copies of the 2–5 repeat allele (S‐DRD4). Twenty infants were homozygous for the short form (s/s) of 5‐HTTLPR while 41 were either heterozygous for the short and the long form (l/s) or were homozygous for the long form (l/l). The infants were observed in a series of standard temperament episodes that elicited fear, anger, pleasure, interest, and activity. L‐DRD4 infants showed less interest in a structured block play situation and more activity in a free play situation. They also displayed less anger in an episode of mild physical restraint. Infants with s/s 5‐HTTLPR showed less fearful distress to stranger approach and less pleasure in a structured play situation than infants with l/l or l/s 5‐HTTLPR. Duration of looking during block play was affected by a significant interaction between DRD4 and 5‐HTTLPR. Shortest duration of looking was associated with the L‐DRD4 and s/s 5‐HTTLPR genotypes. The implications and limitations of these findings are discussed.