Table 1.

Lists of genes that are associated with schizophrenia. A list of specific citations for the table entries is available from the authors. See also (Schizophrenia Working Group of the Psychiatric Genomics, 2014).

I. Gene	II. Evidence	III. Gene product	IV. Known Functions
Genes reported with genome-wide significance, or showing strong evidence for pathogenicity within deletions/duplications
NMDAR/GRIN2A	GWAS	NMDA receptor subunit	Lynchpin of synaptic plasticity at glutamatergic synapses
GRM3	GWAS	Metabotropic glutamate receptor 3 (mGluR3)	May influence synaptic glutamate levels or NMDA receptor exocytosis
AMPAR/GRIA1A	GWAS	Ionotropic glutamate receptor subunit	Influences postsynaptic glutamate responsiveness.
CACNA1C	GWAS	CaV1.2 voltage-gated calcium channel subunit	Important in NMDA-independent synaptic plasticity in the hippocampus
NRGN	GWAS	Neurogranin – calmodulin-binding protein	Contributes to regulation of post-synaptic calcium levels and long-term potentiation
MIR137	GWAS	mir137 - microRNA	Interferes with transcription of target mRNAs including CACNA1C, DPYD, CSMD1, ZNF804A and TCF4
TCF4	GWAS	Transcription Factor 4	Targets may include other important schizophrenia related genes as well as stress/survival and developmental pathways. Haploinsufficiency causes Pitt-Rivers syndrome, a mental retardation syndrome.
C10orf26	GWAS	Unknown	Unknown
CACNB2, CACNA1I, CACNA1C	GWAS	Voltage-gated calcium channel subunit	Unknown
ZNF804A	GWAS	Zinc Finger Protein transcription factor	Unknown
TSNARE1	GWAS
EPHX2	GWAS	Epoxide hydrolyse 2	Inhibition reverses PCP (and NMDA antagonist)-induced changes to behavior in mice
SRR	GWAS	Serine racemase	Converts l-serine to d-serine, a co-agonist of NMDA receptors. Mouse SRR knockouts demonstrate NMDA hypofunction
DRD2	GWAS	Dopamine receptors	DRD2 is the main site of antipsychotic action
SLC38A7	GWAS	Glutamine transporter	May be involved in glutamate recycling in the synaptic cleft
PLCH2	GWAS	Intracellular calcium receptor	Involved in calcium signalling during neural development
NRXN1	Deletion, rare mutation	Multiple splice variants yield neurexins – cell-cell adhesion molecules	Involved in the formation, stabilisation and remodelling of both glutamatergic and glycinergic synapses together with NLGN.
MEF2C	GWAS	Transcription factor	Allosteric modulator of the NMDA receptor
CNNM2	GWAS	Cyclin M2	Important in renal regulation of magnesium
VIPR2	Duplication	G-protein-coupled VIPR receptor	VIP known to regulate NMDA receptor activity in the hippocampus.
Genes with weaker evidence of linkage to schizophrenia
NRG1	Association		NRG1-ErbB4 signalling pathway causes reduction of NMDA currents and long-term plasticity via phosphorylation of NR2B subunit.
ErbB4	Association
G72	Association	d-amino acid oxidase activator	G72 activates DAOA, which in turn degrades d-serine, a potent co-agonist at the glycine site of the NMDA receptor.
DAAO	Association	d-amino acid oxidase
DISC1	Association, linkage	Disrupted in schizophrenia-1	Post-synaptic density protein involved in synaptic spine formation, NMDAR trafficking and presynaptic glutamate release. Also stabilises serine racemase.
DTNBP1	Association, linkage	Dysbindin	Post-synaptic density protein which controls NMDAR expression, NMDA-mediated glutamate currents and glutamate release.
COMT	Linkage, deletion	Catechol-O-methyltransferase	Degrades dopamine and noradrenaline
CHRNA7	Association, linkage	Acetylcholine receptor
GRM5	Rare mutation	Metabotropic glutamate receptor 5 (mGluR5)	Physically coupled to NMDAR at the post-synaptic density; co-activation potentiates NMDA currents
PPEF2	Rare mutation	Calmodulin-binding phosphatase	Influences the levels of mGluR5
LRPB1	Rare mutation	LDL-like receptor	Competes for NMDA binding site on PSD-95 structural protein
LRP1	Rare mutation	LDL-like receptor	Competes for NMDA binding site on PSD-95 structural protein
PRODH	Linkage, deletion, rare mutation	Proline dehydrogynase	NMDA receptor agonist at the glutamate binding site