Rs1611115

rs1611115 (C-1021T) is a SNP near the dopamine beta-hydroxylase (DBH) gene.

per OMIM, the T allele is associated with lower DBH expression in plasma (16 of TT genotype had DBH activity of 4.1, 46 of CT genotype had DBH activity of 25.2, and 112 of CC genotype had DBH activity of 48.1 nmol/min/ml)

Association tests related to affective disorders such as ADHD were performed using four independent samples, healthy volunteers (N = 387), patients with affective disorders (N = 182), adult attention deficit hyperactivity disorder (ADHD) patients (N = 407), and patients with personality disorders (N = 637). Personality disorder patients carrying the DBH TT genotype exhibited higher neuroticism and novelty seeking scores as compared to individuals with the (C;C) or (C;T) genotype. Analyses on the level of the neuroticism and novelty seeking subscales revealed that the DBH (T;T) genotype was primarily associated with personality features related to impulsiveness and aggressive hostility. Also adult ADHD patients carrying the homozygous (T;T) genotypes displayed by significantly increased neuroticism scores; when both personality disorder and adult ADHD patient were analyzed together, (T;T) carriers also displayed by significantly lower conscientiousness levels.

This study concludes that rs1611115(T;T) homozygotes appear to be at increased risk for personality traits related to impulsiveness, aggression, and adult ADHD.

Dopamine-beta-hydroxylase in postural tachycardia syndrome. T allele associated with lower plasma DBH levels, and accounts for up to 52% of variation in plasma DBH, but not linked to increased susceptibility to postural tachycardia syndrome (POTS).