Evidence That Brain MAO A Activity Does Not Correspond to MAO A Genotype in Healthy Male Subjects

BackgroundA functional polymorphism in the promoter region of the monoamine oxidase A (MAO A) gene has two common alleles that are referred to as the high and low MAO A genotypes. We report the first in vivo human study to determine whether there is an association between MAO A genotype and brain MAO A activity in healthy male subjects.MethodsBrain MAO A activity was measured with positron emission tomography and [11C]clorgyline in 38 healthy adult male nonsmokers genotyped for MAO A polymorphism.ResultsThere was no significant difference in brain MAO A activity between the high (n = 26) and low (n = 12) MAO A genotypes.ConclusionsThe lack of an association between the high and low MAO A genotype and brain MAO A activity suggests that this polymorphism by itself does not contribute to differences in brain MAO A activity in healthy adult male subjects.