In conclusion, we found an association of antipsychotic-induced HPRL with rs1799836 of the MAOB gene in (hemizygous) men and rs40184 and rs3863145 variants in the SLC6A3 gene which codes for the dopamine transporter in patients using risperidone/paliperidone. The gene discussed is MAOB; the disease is familial hyperprolactinemia.