16-9763460-T-C

Position:

• chr16-9763460-T-C

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_001134407.3(GRIN2A):​c.4084A>G​(p.Thr1362Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign 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. T1362N) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GRIN2A NM_001134407.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0690

Genes affected

GRIN2A (HGNC:4585): (glutamate ionotropic receptor NMDA type subunit 2A) This gene encodes a member of the glutamate-gated ion channel protein family. The encoded protein is an N-methyl-D-aspartate (NMDA) receptor subunit. NMDA receptors are both ligand-gated and voltage-dependent, and are involved in long-term potentiation, an activity-dependent increase in the efficiency of synaptic transmission thought to underlie certain kinds of memory and learning. These receptors are permeable to calcium ions, and activation results in a calcium influx into post-synaptic cells, which results in the activation of several signaling cascades. Disruption of this gene is associated with focal epilepsy and speech disorder with or without cognitive disability. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2014]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), GRIN2A. . Gene score misZ 2.8278 (greater than the threshold 3.09). Trascript score misZ 3.7088 (greater than threshold 3.09). GenCC has associacion of gene with early-onset epileptic encephalopathy and intellectual disability due to GRIN2A mutation, Landau-Kleffner syndrome, continuous spikes and waves during sleep, complex neurodevelopmental disorder, rolandic epilepsy-speech dyspraxia syndrome, childhood epilepsy with centrotemporal spikes.
• BP4: Computational evidence support a benign effect (MetaRNN=0.041492313).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRIN2A	NM_001134407.3	c.4084A>G	p.Thr1362Ala	missense_variant	13/13	ENST00000330684.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRIN2A	ENST00000330684.4	c.4084A>G	p.Thr1362Ala	missense_variant	13/13	1	NM_001134407.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Landau-Kleffner syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 19, 2016

This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a GRIN2A-related disease. In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. This sequence change replaces threonine with alanine at codon 1362 of the GRIN2A protein (p.Thr1362Ala). The threonine residue is weakly conserved and there is a small physicochemical difference between threonine and alanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.058
BayesDel_addAF	Benign	-0.36	T
BayesDel_noAF	Benign	-0.75
CADD	Benign	3.8
DANN	Benign	0.58
DEOGEN2	Benign	0.38	T;T
Eigen	Benign	-0.88
Eigen_PC	Benign	-0.87
FATHMM_MKL	Benign	0.36	N
LIST_S2	Benign	0.71	.;T
M_CAP	Benign	0.0078	T
MetaRNN	Benign	0.041	T;T
MetaSVM	Benign	-0.97	T
MutationAssessor	Benign	0.55	N;N
MutationTaster	Benign	1.0	D;D;D;N;N;N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.25	N;N
REVEL	Benign	0.076
Sift	Benign	0.95	T;T
Sift4G	Benign	1.0	T;T
Polyphen		0.0	B;B
Vest4		0.029
MutPred		0.35		Loss of phosphorylation at T1362 (P = 0.0367);Loss of phosphorylation at T1362 (P = 0.0367);
MVP		0.46
MPC		0.24
ClinPred		0.066	T
GERP RS		-4.3
Varity_R		0.037
gMVP		0.14

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs77282679; hg19: chr16-9857317;