4-92304709-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_001510.4(GRID2):c.53G>A(p.Trp18Ter) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. 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)
• Consequence: GRID2 NM_001510.4 stop_gained
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.76

Genes affected

GRID2 (HGNC:4576): (glutamate ionotropic receptor delta type subunit 2) The protein encoded by this gene is a member of the family of ionotropic glutamate receptors which are the predominant excitatory neurotransmitter receptors in the mammalian brain. The encoded protein is a multi-pass membrane protein that is expressed selectively in cerebellar Purkinje cells. A point mutation in the mouse ortholog, associated with the phenotype named 'lurcher', in the heterozygous state leads to ataxia resulting from selective, cell-autonomous apoptosis of cerebellar Purkinje cells during postnatal development. Mice homozygous for this mutation die shortly after birth from massive loss of mid- and hindbrain neurons during late embryogenesis. This protein also plays a role in synapse organization between parallel fibers and Purkinje cells. Alternate splicing results in multiple transcript variants encoding distinct isoforms. Mutations in this gene cause cerebellar ataxia in humans. [provided by RefSeq, Apr 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 12 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-92304709-G-A is Pathogenic according to our data. Variant chr4-92304709-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 620343.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRID2	NM_001510.4	c.53G>A	p.Trp18Ter	stop_gained	1/16	ENST00000282020.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRID2	ENST00000282020.9	c.53G>A	p.Trp18Ter	stop_gained	1/16	1	NM_001510.4	P1
GRID2	ENST00000510992.5	c.53G>A	p.Trp18Ter	stop_gained	1/15	1
GRID2	ENST00000505687.5	n.225G>A		non_coding_transcript_exon_variant	1/6	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Sep 07, 2018

The W18X variant in the GRID2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The W18X variant is not observed in large population cohorts (Lek et al., 2016). We interpret W18X as a likely pathogenic variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.50
Cadd	Pathogenic	39
Dann	Uncertain	0.99
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Uncertain	0.83	D
MutationTaster	Benign	1.0	A;A
Vest4		0.71
GERP RS		3.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs1560556892; hg19: chr4-93225860;