Association of multiple DRD2 polymorphisms with anorexia nervosa.

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Background:

• The dopaminergic system is implicated in reward processing and motivation.
• Dysregulation of dopamine signaling has been hypothesized to contribute to the etiology of eating disorders, including anorexia nervosa (AN).
• The dopamine D2 receptor (DRD2) is a key component of the dopaminergic system.

Purpose of the Study:

• To investigate the association between the dopamine D2 receptor gene (DRD2) and anorexia nervosa (AN).
• To examine the role of specific single-nucleotide polymorphisms (SNPs) within the DRD2 gene in AN susceptibility.
• To determine if genetic variations affecting DRD2 expression influence vulnerability to AN.

Main Methods:

• Genotyping of seven single-nucleotide polymorphisms (SNPs) across approximately 75 kbp of the DRD2 gene.
• Case-control association studies and haplotype transmission disequilibrium tests were performed.
• Study population included 191 AN probands, 457 affected relatives, and 98 healthy controls.

Main Results:

• Statistically significant associations were found between AN diagnosis and the -141 C/- insertion/deletion (-141 Indel) and multiple exon seven polymorphisms in DRD2.
• These specific polymorphisms (-141 Indel and exon seven SNPs 939Y and 957Y) were shown to affect DRD2 transcription and transcript stability.
• Significant linkage disequilibrium between the -141 Indel and two exon seven SNPs was observed in AN probands over a considerable distance (>50 kbp).

Conclusions:

• Functional polymorphisms in the DRD2 gene, influencing transcription and translation efficiency, may contribute to the genetic vulnerability to anorexia nervosa.
• Genetically transmitted variations in D2 dopamine receptor expression are potentially implicated in the etiology of AN.
• These findings highlight the role of the dopaminergic system, specifically the dopamine D2 receptor, in the neurobiological underpinnings of AN.