16-9769001-G-T

Position:

• chr16-9769001-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_001134407.3(GRIN2A):​c.2445C>A​(p.Asp815Glu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. D815H) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GRIN2A NM_001134407.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:1
• Conservation: PhyloP100: 4.13

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 Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_001134407.3
• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRIN2A	NM_001134407.3	c.2445C>A	p.Asp815Glu	missense_variant	12/13	ENST00000330684.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRIN2A	ENST00000330684.4	c.2445C>A	p.Asp815Glu	missense_variant	12/13	1	NM_001134407.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Landau-Kleffner syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 24, 2018

This sequence change replaces aspartic acid with glutamic acid at codon 815 of the GRIN2A protein (p.Asp815Glu). The aspartic acid residue is highly conserved and there is a small physicochemical difference between aspartic acid and glutamic acid. This variant is present in population databases (rs754929310, ExAC 0.009%). This variant has not been reported in the literature in individuals with GRIN2A-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Uncertain	0.022	T
BayesDel_noAF	Benign	-0.21
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.80	D;.;.;D
Eigen	Benign	0.12
Eigen_PC	Benign	0.16
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.92	.;D;D;D
M_CAP	Pathogenic	0.47	D
MetaRNN	Uncertain	0.68	D;D;D;D
MetaSVM	Benign	-0.97	T
MutationAssessor	Benign	1.2	L;.;L;L
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Uncertain	-3.6	D;.;D;D
REVEL	Benign	0.28
Sift	Benign	0.24	T;.;T;T
Sift4G	Benign	0.077	T;T;T;T
Polyphen		0.99	D;.;.;D
Vest4		0.69
MutPred		0.69		Gain of disorder (P = 0.1545);.;Gain of disorder (P = 0.1545);Gain of disorder (P = 0.1545);
MVP		0.81
MPC		0.86
ClinPred		0.99	D
GERP RS		3.5
Varity_R		0.79
gMVP		0.84

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: rs754929310; hg19: chr16-9862858;