NM_001134407.3:c.2146G>A

Variant names:

• chr16-9822286-C-T
• rs762659685
• NM_001134407.3:c.2146G>A

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PS1_Moderate PM1 PM2 PP2 PP3_Moderate PP5_Very_Strong

The NM_001134407.3(GRIN2A):​c.2146G>A​(p.Ala716Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,306 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in UniProt.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GRIN2A NM_001134407.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7 O:1
• Conservation: PhyloP100: 7.81

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 Pathogenic. Variant got 17 ACMG points.

• PS1: Transcript NM_001134407.3 (GRIN2A) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt
• PM1: In a helix (size 8) in uniprot entity NMDE1_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_001134407.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the GRIN2A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 92 curated pathogenic missense variants (we use a threshold of 10). The gene has 175 curated benign missense variants. Gene score misZ: 2.8278 (below the threshold of 3.09). Trascript score misZ: 3.7088 (above the threshold of 3.09). GenCC associations: The gene is linked to 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.914
• PP5: Variant 16-9822286-C-T is Pathogenic according to our data. Variant chr16-9822286-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 205656.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-9822286-C-T is described in Lovd as [Pathogenic]. Variant chr16-9822286-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GRIN2A	NM_001134407.3	c.2146G>A	p.Ala716Thr	missense_variant	Exon 10 of 13	ENST00000330684.4	NP_001127879.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GRIN2A	ENST00000330684.4	c.2146G>A	p.Ala716Thr	missense_variant	Exon 10 of 13	1	NM_001134407.3	ENSP00000332549.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461306 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726980

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Landau-Kleffner syndrome Pathogenic:3 Other:1

-

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Jan 28, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 716 of the GRIN2A protein (p.Ala716Thr). This variant is present in population databases (rs762659685, gnomAD 0.01%). This missense change has been observed in individual(s) with epilepsy (PMID: 23933820). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 205656). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt GRIN2A protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GRIN2A function (PMID: 27839871). For these reasons, this variant has been classified as Pathogenic. -

Apr 16, 2018

Génétique des Maladies du Développement, Hospices Civils de Lyon

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 01, 2019

Institute of Human Genetics, University of Leipzig Medical Center

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

not provided Pathogenic:3

Sep 01, 2016

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 02, 2014

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

p.Ala716Thr (GCC>ACC): c.2146 G>A in exon 11 of the GRIN2A gene (NM_000833.3). The A716T variant has been previously reported as a potentially deleterious variant in a family with atypical Rolandic epilepsy, verbal dyspraxia, and cognitive impairment (Lesca et al., 2013). The A716T mutation was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. A716T is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. A716T alters a highly conserved position in the extracellular domain, and in silico analysis predicts this variant is probably damaging to the protein structure/function. Therefore, this variant is a strong candidate for a pathogenic mutation, however the possibility that it is a benign variant cannot be excluded. The variant is found in EPILEPSY panel(s). -

Nov 07, 2016

Eurofins Ntd Llc (ga)

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases Pathogenic:1

Jan 08, 2024

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2146G>A (p.A716T) alteration is located in coding exon 9 of the GRIN2A gene. This alteration results from a G to A substitution at nucleotide position 2146, causing the alanine (A) at amino acid position 716 to be replaced by a threonine (T). This allele was reported in one heterozygous individual in population-based cohorts in the Genome Aggregation Database (gnomAD). This variant has been reported as a heterozygous de novo finding in multiple unrelated patients with clinical features of GRIN2A-related speech disorders and epilepsy (Li, 2020; Lee, 2021. external communications). This has also been shown to segregate with disease in a family with atypical rolandic epilepsy, verbal dyspraxia, cognitive impairment of variable degrees (Lesca, 2013). This amino acid position is highly conserved in available vertebrate species. This missense alteration is located in a region that has a low rate of benign missense variation (Lek, 2016; Firth, 2009). This alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, this alteration is classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D;.;.;D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	.;D;D;D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.91	D;D;D;D
MetaSVM	Benign	-0.58	T
MutationAssessor	Uncertain	2.5	M;.;M;M
PrimateAI	Pathogenic	0.86	D
PROVEAN	Uncertain	-3.9	D;.;D;D
REVEL	Pathogenic	0.68
Sift	Uncertain	0.0010	D;.;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0	D;.;.;D
Vest4		0.94
MutPred		0.73		Loss of helix (P = 0.079);.;Loss of helix (P = 0.079);Loss of helix (P = 0.079);
MVP		0.85
MPC		2.6
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.95
gMVP		0.94

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: rs762659685; hg19: chr16-9916143; COSMIC: COSV58032355;