We have investigated the role of ten polymorphisms in these genes (RLN3 rs12327666, rs1982632, and rs7249702, RLN3R1 rs42868, rs6861957, rs7702361, and rs35399, and RLN3R2rs11264422, rs1018730 and rs12124383) in the occurrence of metabolic syndrome phenotypes (obesity, diabetes, hypercholesterolemia, hypertrigyceridemia, and hypertension) in a cross-sectional cohort of 419 US Caucasian patients treated with antipsychotic drugs.