Table 2.

Genetic associations related to interval timing disorders.

	gene	clinical association/alteration	reference
humans	catechol-O-methyltransferase (COMT Val158Met polymorphism)	interval timing impaired in the suprasecond range and effect of reward magnitude	[118,119]
	dopamie receptor type 2 (DRD2/ANKK1-Taq1a polymorphism)	poorer performance with perceptual timing task and effect of reward magnitude	[118,119]
animals	DAT−/− mice	complete loss of temporal control. Hyperactivity and learning impairment; insensitive to psychostimulants	[120]
	D2R transgenic mice	impairment in timing accuracy and precision. Impairment in tasks that require working memory and behavioural flexibility	[115]