PLPPR4 and psychiatric disorder: In this translational study, we analyzed intermediate phenotypes of psychiatric disorders induced by a heterozygous loss-of-function single-nucleotide polymorphism (SNP) of the PRG-1 gene (PRG-1R345T/WT) in human subjects and compared it to the effects induced by Prg-1 gene deficiency (Prg-1−/− and Prg-1R346T/WT) in mice.