P677. Sex-Specific Polygenic Regulation of Dopamine Synthesis in Striatum in Vivo

Striatal presynaptic dopamine synthesis is implicated in neuropsychiatric illnesses like schizophrenia but shows considerable unexplained individual variability. We hypothesized that cumulative functional genetic variation in a network of proteins regulating tyrosine hydroxylase (TH), the dopamine synthesis rate-limiting enzyme, would contribute to dopamine synthesis capacity in the living human brain, measured by [18F]-FDOPA PET. Given prior work suggesting sex differences in the regulation of dopamine, we also tested for sex-specific effects.