VNTR polymorphism in the monoamine oxidase A promoter region and cerebrospinal fluid catecholamine concentrations in forensic autopsy cases

Monoamine oxidase A (MAOA) plays important roles in the metabolism of catecholamines and modulates adrenergic, noradrenergic, and dopaminergic signaling. A polymorphic promoter variable number tandem repeat (VNTR) locus (MAOA-uVNTR) is located approximately 1.2 kb upstream from MAOA exon 1. Functional studies revealed that MAOA-uVNTR affects gene expression. In the present study, we examined the frequencies of MAOA-uVNTR alleles in Japanese autopsy cases, in which amphetamines or psychotropic drugs were not detected. In total, 87 males and 35 females were evaluated and investigated for the possible effect of MAOA-uVNTR polymorphisms on cerebrospinal fluid (CSF) catecholamine concentrations. In males, there was no significant association between MAOA-uVNTR polymorphisms and CSF adrenaline (Adr), noradrenaline (Nad), or dopamine (DA) levels. In contrast, females who were homozygous for the 3-repeat allele (i.e., 3/3 genotype carriers) had higher CSF levels of Adr (p =  0.024) and DA (p =  0.035) than individuals who were heterozygous or homozygous for the 4-repeat allele (3/4 and 4/4, respectively). We found no significant association between MAOA-uVNTR polymorphisms and CSF Nad levels in females. Thus, the results of the present study indicated that MAOA-uVNTR polymorphism influences CSF Adr and DA levels in females.