No association between dopamine D1, D2, and D3 receptor genes and manic–depressive illness

Background: The dopaminergic receptor genes are candidate genes for manic–depressive illness (MDI). To test this putative involvement we used a case–control study on samples from the native population of the northwest part of France. Methods: Fifty patients for D1 and D2, 61 patients for D3, and 86–223 controls were tested. Results: No significant association was found between allelic frequencies or genotype counts and MDI, even when the data were pooled with those from published studies. Conclusions: Single mutations of either of the studied receptor genes are not major determinants of MDI.