chr16-9763807-T-C

Position:

• chr16-9763807-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 5P and 4B. PP2 PP3_Strong BS2

The NM_001134407.3(GRIN2A):​c.3737A>G​(p.Tyr1246Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,870 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 Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. Y1246Y) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: GRIN2A NM_001134407.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.58

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 1 ACMG points.

• 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
• BS2: High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRIN2A	NM_001134407.3	c.3737A>G	p.Tyr1246Cys	missense_variant	13/13	ENST00000330684.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRIN2A	ENST00000330684.4	c.3737A>G	p.Tyr1246Cys	missense_variant	13/13	1	NM_001134407.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251324 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135824

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461870 Hom.: 0 Cov.: 33 AF XY: 0.00000825 AC XY: 6 AN XY: 727242

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

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

Labcorp Genetics (formerly Invitae), Labcorp

Oct 30, 2017

This variant has not been reported in the literature in individuals with GRIN2A-related disease. 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. 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 disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant is present in population databases (rs779437393, ExAC 0.001%). This sequence change replaces tyrosine with cysteine at codon 1246 of the GRIN2A protein (p.Tyr1246Cys). The tyrosine residue is highly conserved and there is a large physicochemical difference between tyrosine and cysteine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D;.;.;D
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	.;D;D;D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.94	D;D;D;D
MetaSVM	Benign	-0.37	T
MutationAssessor	Uncertain	2.8	M;.;M;M
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Pathogenic	-4.9	D;.;D;D
REVEL	Uncertain	0.57
Sift	Pathogenic	0.0	D;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;.;.;D
Vest4		0.88
MutPred		0.81		Loss of stability (P = 0.1169);.;Loss of stability (P = 0.1169);Loss of stability (P = 0.1169);
MVP		0.72
MPC		1.0
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.73
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: rs779437393; hg19: chr16-9857664;