In a cohort of pediatric patients with attention deficit hyperactivity disorder (ADHD), the prevalence of having at least one minor dysfunctional allele was 78.5% [17], and in women with fibromyalgia, the prevalence of genetic DAO deficiency was 74.5% based on alterations in the four variants of the AOC1 gene [18]. The gene discussed is AOC1; the disease is attention deficit-hyperactivity disorder.