Regarding the NOS1 ex1f-VNTR our study supports the previously reported influence on impulsivity, lending further support to the hypothesis that this genetic variant underlies impulsive behavior.
Impulsivity SNAP-IV scores were also significantly different according to NOS1rs478597 polymorphisms in adults with ADHD (F = 6.282; adjusted P-value = 0.026).
Also, reduced NOS1 expression in the striatum determined by a length polymorphism in a NOS1 promoter (NOS1 ex1f-VNTR) goes along with a variety of impulsive behaviors.
A functional promoter polymorphism of the nitric oxide synthase 1 gene first exon 1f variable number tandem repeat (NOS1 ex1f-VNTR) is associated with impulsivity and related psychopathology.
A functional variable number of tandem repeats (VNTR) polymorphism in the promoter region of the alternative first exon 1f of NOS1 is associated with various functions of human behavior, for example increased impulsivity, while another, non-functional variant was linked to decreased verbal working memory and a heightened risk for schizophrenia.
Further, several polymorphisms of neuronal nitric oxide synthase (NOS1) gene have been reported to be associated with impulsivity, aggression and suicide attempts.
Impulsivity and in particular the aspects of adaptive impulsivity (e.g. fast decision-making and excitement-seeking behaviour) were higher in subjects with the NOS1 ex1f-VNTR short/short genotype if they belonged to the platelet MAO medium activity (interquartile) range.
The findings give additional evidence that NOS-I is involved in the regulation of impulsive personality traits and support the notion that the NOS1 gene takes part in the regulation of social behavior.