The cDNA sequence of the gene encoding human metabotropic glutamate receptor type 7 (mGluR7) contains the single nucleotide polymorphism 1536A > T [GenBank sequence X94552 (Makoff et al., 1996)]. This sequence variation is predicted to result in an amino acid change (F433Y) in the gene product and thus has the potential to affect receptor function. Since disturbances in glutamate function have been implicated in the pathophysiology of schizophrenia, we have used a novel and robust polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay to genotype this polymorphism in a case-control sample comprising 181 schizophrenic patients and 182 group-matched unaffected individuals. No evidence was found for association between this polymorphism and schizophrenia. We have also localised mGluR7 to chromosome 3p25-22 using radiation hybrid (RH) mapping.