Abstract: The present invention relates generally to a GPR109A niacin receptor. The present invention relates more particularly to assessing a GPR109A polymorphism in an individual, wherein the GPR109A polymorphism is indicative of the subject's risk for an adverse reaction to the administration of a GPR109A receptor agonist, wherein the adverse reaction is associated with stimulation of MAP kinase activity by the GPR109A receptor agonist. More specifically, the present invention relates to assessing a GPR109A polymorphism in an individual and determining the level of risk for the subject for experiencing an adverse reaction, wherein the subject's GPR109A zygosity is predictive of the risk for a cutaneous flushing response that can be experienced following administration of a GPR109A receptor agonist.

Abstract: The invention provides a method of identifying a niacin receptor modulator with reduced flushing effect compared to niacin or a niacin analog, comprising determining the MAP kinase activity of said modulator, wherein a decrease in MAP kinase activity induced by said modulator compared to MAP kinase activity induced by niacin or a niacin analog indicates that said modulator has reduced flushing effect when compared to niacin or a niacin analog.