rs1555488144

Positions:

• chr16-9798454-C-T

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_001134407.3(GRIN2A):​c.2179G>A​(p.Ala727Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,650 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GRIN2A NM_001134407.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 7.77

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]

GRIN2A (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 17 ACMG points.

• PM1: In a topological_domain Extracellular (size 170) in uniprot entity NMDE1_HUMAN there are 45 pathogenic changes around while only 1 benign (98%) 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.942
• PP5: Variant 16-9798454-C-T is Pathogenic according to our data. Variant chr16-9798454-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 433124.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GRIN2A	NM_001134407.3	c.2179G>A	p.Ala727Thr	missense_variant	11/13	ENST00000330684.4	NP_001127879.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GRIN2A	ENST00000330684.4	c.2179G>A	p.Ala727Thr	missense_variant	11/13	1	NM_001134407.3	ENSP00000332549.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461650 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727136

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: 0.0000187

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Landau-Kleffner syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 05, 2023	This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 727 of the GRIN2A protein (p.Ala727Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of GRIN2A-related conditions (PMID: 23933819, 28109652; Invitae). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 433124). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GRIN2A protein function. Experimental studies have shown that this missense change affects GRIN2A function (PMID: 27839871). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, no assertion criteria provided	research	Gene Discovery Core-Manton Center, Boston Children's Hospital	Feb 14, 2020	This variant is interpreted as Pathogenic for epilepsy and episodic atazia; Autosomal Dominant. PS2-De novo (both maternity and paternity confirmed) in a patient with the disease and no family history. PS3- Well-established in vitro or in vivo functional studies supportive of a damaging effect on the gene or gene product, PMID:27839871. PM1- Located in a mutational hot spot and/or critical and well-established functional domain (e.g., active site of an enzyme) without benign variation. PM2- Absent from controls in gnomad.PP3- Multiple lines of computational evidence support a deleterious effect on the gene or gene product. (conservation, evolutionary, splicing impact, etc.). PP5- Reputable source recently reports variant as pathogenic, but the evidence is not available to the laboratory to perform an independent evaluation (PMID: 23933819, PMID: 28109652) -
Pathogenic, criteria provided, single submitter	clinical testing	Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India	-	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 14, 2023	Identified in individuals with epilepsy in the published literature with either unknown segregation or inheritance from an unaffected parent (Lemke et al., 2013; von Stulpnagel et al., 2017); Published functional studies demonstrate reduced glutamate potency compared to wild type (Swanger et al., 2016); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 23933819, 29358611, 28109652, 35936491, 36516565, 27839871) -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Oct 01, 2018	- -

Childhood epilepsy with centrotemporal spikes Pathogenic:1

Pathogenic, no assertion criteria provided

case-control

Bioinformatics Core, Luxembourg Center for Systems Biomedicine

Jan 01, 2017

CAADphred>15 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;.;.;D
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Pathogenic	0.99	.;D;D;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.94	D;D;D;D
MetaSVM	Uncertain	-0.034	T
MutationAssessor	Pathogenic	2.9	M;.;M;M
PrimateAI	Pathogenic	0.90	D
PROVEAN	Uncertain	-3.6	D;.;D;D
REVEL	Uncertain	0.53
Sift	Uncertain	0.0010	D;.;D;D
Sift4G	Uncertain	0.010	D;D;D;D
Polyphen		0.99	D;.;.;D
Vest4		0.98
MutPred		0.83		Gain of sheet (P = 0.0477);.;Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);
MVP		0.86
MPC		2.6
ClinPred		0.99	D
GERP RS		4.2
Varity_R		0.91
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: rs1555488144; hg19: chr16-9892311; COSMIC: COSV58051418;