rs1555494671

Positions:

• chr16-9840647-C-A
• chr16-9840647-C-G
• chr16-9840647-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1 PM2 PP3_Strong PP5_Moderate

The NM_001134407.3(GRIN2A):​c.1651G>T​(p.Glu551Ter) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: GRIN2A NM_001134407.3 stop_gained, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P: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 16 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 16-9840647-C-A is Pathogenic according to our data. Variant chr16-9840647-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 2128410.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GRIN2A	NM_001134407.3	c.1651G>T	p.Glu551Ter	stop_gained, splice_region_variant	7/13	ENST00000330684.4	NP_001127879.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GRIN2A	ENST00000330684.4	c.1651G>T	p.Glu551Ter	stop_gained, splice_region_variant	7/13	1	NM_001134407.3	ENSP00000332549	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Landau-Kleffner syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 20, 2022

This variant has not been reported in the literature in individuals affected with GRIN2A-related conditions. For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Glu551*) in the GRIN2A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GRIN2A are known to be pathogenic (PMID: 23933819, 23933820). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	58
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Uncertain	0.97	D
MutationTaster	Benign	1.0	A;A;A;A;A;A
Vest4		0.92
GERP RS		5.3

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.98
SpliceAI score (max)		0.65		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.51		Position offset: 33
DS_DL_spliceai		0.65		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555494671; hg19: chr16-9934504;