Association studies using candidate genes

Caveats aside, the five dopamine receptors remain candidates in disease. The pharmacological properties that have been used to group them into dopamine Dj-like and dopamine D -like receptors may also be useful to consider when surveying the dopamine receptor gene association studies. For the most part, the D -like dopamine receptors Dj (50-52) and Dj (53) have not been as widely associated with disease as the D dopamine receptors. The D -like receptors D (54), D3 (55), and D (56) have similar dopamine sensitivities and are much more polymorphic than the Dj-like receptors (49,57). 

At least four experimental approaches have been used to study the role of gene expression in association with arousal states (a) gene expression in association with spontaneous variation in arousal state (b) gene expression associated with SD (c) gene expression associated with RS after SD and (d) gene expression associated with drug-induced sleep. In this section, we will primarily focus on approaches in which specific candidate genes have been studied in association with SD and RS. 

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