MAO stands for Monoamine Oxidase A and is one of several genes/enzymes responsible for the processing/digestion of dopamine, serotonin, norepinephrine and epinephrine. This methyl enzyme is dependent on adequate amounts of riboflavin (one of the B vitamins) to work correctly. When the gene is mutated there is an increased risk of mood and attention related issues such as depression, aggression, anger, ADHD, and maybe social personality disorder. Heterozygous or homozygous mutations can be an indicator of why certain chemical imbalances occur in an individual leading to mild to moderate to severe manifestations. Of course, genetic mutations are only a piece of the puzzle. The environment which your DNA makes copies is dependent on many factors. The chemical imbalances are influenced by many factors. For example, most of the serotonin is made in the gut. If there is bacterial dysbiosis, yeast overgrowth, overconsumption of sugar the body may experience challenges in making enough serotonin. Questions to ask yourself if you carry a partial or full mutation is whether or not your diet and lifestyle helps your imperfections or acerbates them? Are you supporting your unique genetic makeup?