DRD4 is the dopamine D4 receptor gene and is associated with ADHD and novelty seeking behaviors. It has been proposed that novelty seeking is associated with impulsivity. Mice deficient for DRD4 have shown less behavioral responses to novelty. 5HT2A is the serotonin receptor gene. The serotonin 2A receptor gene has been associated with both hyper locomotion, ADHD, as well as impulsivity. Subjects with a particular polymorphism of the 5HT2A gene made more commission errors during a punishment-reward condition in a go/no-go task. HTR2B a serotonin receptor gene. CTNNA2 encodes for a brain-expressed α-catenin that has been associated with Excitement-Seeking in a genome-wide association study (GWAS) of 7860 individuals. Intervention
Interventions to impact impulsivity generally
While impulsivity can take on pathological forms (e.g. substance use disorder, ADHD), there are less severe, non-clinical forms of problematic impulsivity in many peoples daily lives. Research on the different facets of impulsivity can inform small interventions to change decision making and reduce impulsive behavior For example, changing cognitive representations of rewards (e.g. making long term rewards seem more concrete) and/or creating situations of "precommitment" (eliminating the option of changing ones mind later)  can reduce the preference for immediate reward seen in delay discounting. Brain training
Brain training interventions include laboratory-based interventions (e.g. training using tasks like go/no go) as well as community, family, and school based interventions that are ecologically valid (e.g. teaching techniques for regulating emotions or behaviors) and can be used with individuals with non-clinical levels of impulsivity.
Resisting the urge to act on impulses is important to teach children, because it teaches the value of delayed gratification. Many psychological problems are characterized by a loss of control or a lack of control in specific situations. Usually, this lack of control is part of a pattern of behavior that also involves other maladaptive thoughts and actions, such as substance abuse problems or sexual disorders like the paraphilias (e.g. pedophilia and exhibitionism). When loss of control is only a component of a disorder, it usually does not have to be a part of the behavior pattern, and other symptoms must also be present for the diagnosis to be made. (Franklin)

The five traits that can lead to impulsive actions
For many years it was understood that impulsivity is a trait but with further analysis it can be found that there were five traits that can lead to impulsive actions:
positive urgency, 
negative urgency,
sensation seeking, 
lack of planning, and
lack of perseverance. Associated behavioral and societal problems
Attention-deficit hyperactivity disorder
Attention deficit-hyperactivity disorder (ADHD) is a multiple component disorder involving inattention, impulsivity, and hyperactivity. The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) breaks ADHD into three subtypes according to the behavioral symptoms:
Attention-Deficit/Hyperactivity Disorder Predominantly Inattentive Type,
Attention-Deficit/Hyperactivity Disorder Predominantly Hyperactive-Impulsive Type, and
Attention-Deficit/Hyperactivity Disorder Combined Type. Predominantly hyperactive-impulsive type symptoms may include
fidgeting and squirming in seats,
talking nonstop,
dashing around and touching or playing with anything in sight,
having trouble sitting still during dinner/school/story time,
being constantly in motion, and
having difficulty doing quiet tasks or activities.