NM_021956.5:c.2303C>G

Variant names:

• chr6-102035558-C-G
• rs748950853
• NM_021956.5:c.2303C>G

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_021956.5(GRIK2):​c.2303C>G​(p.Thr768Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T768A) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: GRIK2 NM_021956.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.91
• Publications: 0 publications found

Genes affected

GRIK2 (HGNC:4580): (glutamate ionotropic receptor kainate type subunit 2) Glutamate receptors are the predominant excitatory neurotransmitter receptors in the mammalian brain and are activated in a variety of normal neurophysiologic processes. This gene product belongs to the kainate family of glutamate receptors, which are composed of four subunits and function as ligand-activated ion channels. The subunit encoded by this gene is subject to RNA editing at multiple sites within the first and second transmembrane domains, which is thought to alter the structure and function of the receptor complex. Alternatively spliced transcript variants encoding different isoforms have also been described for this gene. Mutations in this gene have been associated with autosomal recessive cognitive disability. [provided by RefSeq, Jul 2008]

GRIK2 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AR, AD Classification: DEFINITIVE, MODERATE Submitted by: ClinGen
• intellectual disability, autosomal recessive 6

  Inheritance: AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• neurodevelopmental disorder with impaired language and ataxia and with or without seizures

  Inheritance: AD Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• autosomal recessive non-syndromic intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.753

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_021956.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRIK2	NM_021956.5	MANE Select	c.2303C>G	p.Thr768Ser	missense	Exon 15 of 17	NP_068775.1
	GRIK2	NM_001166247.1		c.2303C>G	p.Thr768Ser	missense	Exon 14 of 17	NP_001159719.1
	GRIK2	NM_175768.3		c.2303C>G	p.Thr768Ser	missense	Exon 14 of 17	NP_786944.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRIK2	ENST00000369134.9	TSL:5 MANE Select	c.2303C>G	p.Thr768Ser	missense	Exon 15 of 17	ENSP00000358130.6
	GRIK2	ENST00000421544.6	TSL:1	c.2303C>G	p.Thr768Ser	missense	Exon 17 of 19	ENSP00000397026.1
	GRIK2	ENST00000369138.5	TSL:1	c.2303C>G	p.Thr768Ser	missense	Exon 14 of 17	ENSP00000358134.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 25

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Nov 12, 2015

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Uncertain	0.035	T
BayesDel_noAF	Benign	-0.19
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.64	D
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D
M_CAP	Benign	0.027	D
MetaRNN	Pathogenic	0.75	D
MetaSVM	Benign	-1.0	T
MutationAssessor	Pathogenic	3.0	M
PhyloP100		7.9
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-3.4	D
REVEL	Uncertain	0.45
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.017	D
Polyphen		1.0	D
Vest4		0.74
MutPred		0.78		Gain of glycosylation at T768 (P = 0.0424)
MVP		0.65
MPC		2.1
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.94
gMVP		0.77
Mutation Taster		=24/76	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs748950853; hg19: chr6-102483433;