There were no significant group differences in COMTVal158Met alleles and genotype frequencies between patients and controls, for all EDs pooled together [range of odds ratios (ORs): 0.96-1.04, p-values: 0.46-0.97, I<sup>2</sup> = 0%] and when analysing separately patients with AN (ORs: 0.94-1.04, p-values: 0.31-0.61, I<sup>2</sup> = 0%) or BN (ORs: 0.80-1.09, p-values: 0.28-0.64, I<sup>2</sup> = 0-44%).
Starvation affects DA release in the prefrontal cortex of patients with anorexia nervosa with different effects on executive functioning and prefrontal functional connectivity according to the COMT genotype.
Genetic variation at the catechol-O-methyltransferase (COMT) gene has been significantly associated with risk for various neuropsychiatric conditions such as schizophrenia, panic disorder, bipolar disorders, anorexia nervosa and others.
These findings seem to suggest that a turnover of catecholamines, connected with polymorphism determining high activity of COMT enzyme, is connected with the risk of ED occurrence, particularly anorexia nervosa.
Specifically, haplotype B [COMT-186C-408G-472G(158Val)-ARVCF-659C(220Pro)-524T(175Val)] was preferentially transmitted (P < 0.001) from parents of AN-R patients to their affected daughters, while haplotype A [COMT-186T-408C-472A(158Met)-ARVCF-659T(220Leu)-524C(175Ala)] was preferentially (P = 0.01) not transmitted.
Our study suggests that the COMT gene is associated with genetic susceptibility to AN, and that individuals homozygous for the high activity allele (HH) have a two-fold increased risk for development of the disorder.