Genetic variables of the glutamatergic system associated with treatment-resistant depression: A review of the literature

Table 1 Summary of studies on main candidate genes of the glutamatergic system related to depression

Receptor	Gene	Marker	Ref.	Result
NMDA	GRIN2A	rs16966731	Chen et al[79], 2021	T allele associated with antidepressant effect of ketamine
	GRIN2B	rs1805502	Zhang et al[69], 2014	G allele associated with TRD
			Arnold et al[70], 2009	GT haplotype increased risk of TRD
		rs890	Zhang et al[69], 2014	C allele associated with TRD
			Arnold et al[70], 2009
		rs2268115	Sokolowski et al[72], 2013	Associated with suicide attempts
		rs220557	Sokolowski et al[72], 2013	Associated with suicide attempts
AMPA	GRIA2	rs4302506	Chiesa et al[91], 2012	C allele associated with a lower age of onset in MDD
		rs4400397	Chiesa et al[91], 2012	C allele associated with a lower age of onset in MDD
	GRIA3	rs4825476	Laje and McMahon[17], 2007	G allele associated with suicidal ideation
Kainate	GRIK4	rs1954787	Horstmann et al[94], 2010	CC haplotype associated with response to antidepressants
			Serretti et al[95], 2012	No significant associations
		rs12800734	Horstmann et al[94], 2010	GG haplotype associated with response to antidepressants
			Serretti et al[95], 2012	No significant associations

NMDA: N-methyl-D-aspartic acid; AMPA: α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid; TRD: Treatment-resistant depression; MDD: Major depressive disorder; T: Thymine; G: Guanine; C: Cytosine.