4-92590204-TGAG-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PM4_Supporting BS1_Supporting

The NM_001510.4(GRID2):c.166_168del(p.Glu56del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,611,508 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: GRID2 NM_001510.4 inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.32

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_001510.4. Strenght limited to Supporting due to length of the change: 1aa.
• BS1: Variant frequency is greater than expected in population eas. gnomad4_exome allele frequency = 0.0000226 (33/1459358) while in subpopulation EAS AF= 0.000656 (26/39648). AF 95% confidence interval is 0.000459. There are 0 homozygotes in gnomad4_exome. There are 15 alleles in male gnomad4_exome subpopulation. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRID2	NM_001510.4	c.166_168del	p.Glu56del	inframe_deletion	2/16	ENST00000282020.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRID2	ENST00000282020.9	c.166_168del	p.Glu56del	inframe_deletion	2/16	1	NM_001510.4	P1
GRID2	ENST00000510992.5	c.166_168del	p.Glu56del	inframe_deletion	2/15	1
GRID2	ENST00000505687.5	n.338_340del		non_coding_transcript_exon_variant	2/6	1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152150 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000194

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251284 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135790

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000163

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000226 AC: 33 AN: 1459358 Hom.: 0 AF XY: 0.0000207 AC XY: 15 AN XY: 726170

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000656

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000631

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152150 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74336

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000194

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 26, 2022

This variant, c.166_168del, results in the deletion of 1 amino acid(s) of the GRID2 protein (p.Glu56del), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs763741990, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with GRID2-related conditions. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Computational scores

Source: dbNSFP v4.3

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: rs763741990; hg19: chr4-93511355;