Details

Autor(en) / Beteiligte

• HARDMAN, C.A.
• ROGERS, P.J.
• MUNAFÒ, M.

Titel

Are genetic association studies useful for obesity research? The cases of DRD2 and OPRMI

Ist Teil von

• Appetite, 2012-10, Vol.59 (2), p.627-627

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2012

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• Obesity is highly heritable and a growing number of studies have attempted to identify candidate genes that are associated with BMI. The dopamine D2 receptor (DRD2) gene and the mu-opioid receptor (OPRM1) gene appear promising candidates in this respect due to evidence that both the dopaminergic and opioid systems are involved in obesity and over-eating. However, studies conducted to date have yielded inconsistent results – it is not clear, for example, whether the minor allele of the OPRM1 gene predisposes to obesity or alternatively is a protective factor. The current study aimed to determine whether associations exist between these candidate genes and body weight in a large representative sample (the Avon Longitudinal Study of Parents and Children). Importantly, this cohort permits examination of associations both cross-sectionally and longitudinally, and in children and parents (n=3700 and n=2638, respectively). Our analyses show a lack of association between DRD2 and OPRM1 genotypes and change in BMI and waist circumference (e.g., for DRD2, per allele dosage effect on BMI=0.01 kg/m2, 95% CI: −0.14, 0.15). We suggest that previous inconsistent results are due to low power of genetic association studies, and a tendency for their findings to become immune to refutation by empirical research. The history of genetic association studies in psychiatry is one of initial promise followed by subsequent disappointment (due in large part to insufficiently powered studies). It is imperative to avoid these mistakes from being repeated in the obesity literature.