X-123184599-C-A

Position:

• chrX-123184599-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000828.5(GRIA3):​c.64C>A​(p.Leu22Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000000913 in 1,095,634 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 21)
  • Exomes 𝑓: 9.1e-7 (0 hom. 1 hem.)
• Consequence: GRIA3 NM_000828.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.05

Genes affected

GRIA3 (HGNC:4573): (glutamate ionotropic receptor AMPA type subunit 3) Glutamate receptors are the predominant excitatory neurotransmitter receptors in the mammalian brain and are activated in a variety of normal neurophysiologic processes. These receptors are heteromeric protein complexes composed of multiple subunits, arranged to form ligand-gated ion channels. The classification of glutamate receptors is based on their activation by different pharmacologic agonists. The subunit encoded by this gene belongs to a family of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate)-sensitive glutamate receptors, and is subject to RNA editing (AGA->GGA; R->G). Alternative splicing at this locus results in different isoforms, which may vary in their signal transduction properties. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2691496).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GRIA3	NM_000828.5	c.64C>A	p.Leu22Ile	missense_variant	1/16	ENST00000622768.5	NP_000819.4
GRIA3	NM_007325.5	c.64C>A	p.Leu22Ile	missense_variant	1/16	ENST00000620443.2	NP_015564.5
GRIA3	NM_001256743.2	c.64C>A	p.Leu22Ile	missense_variant	1/4		NP_001243672.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GRIA3	ENST00000620443.2	c.64C>A	p.Leu22Ile	missense_variant	1/16	1	NM_007325.5	ENSP00000478489	P4
GRIA3	ENST00000622768.5	c.64C>A	p.Leu22Ile	missense_variant	1/16	5	NM_000828.5	ENSP00000481554	A1

Frequencies

GnomAD3 genomes Cov.: 21

GnomAD3 exomes AF: 0.00000545 AC: 1 AN: 183412 Hom.: 0 AF XY: 0.0000147 AC XY: 1 AN XY: 67846

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.000134

Gnomad EAS exome AF: 0.00

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: 9.13e-7 AC: 1 AN: 1095634 Hom.: 0 Cov.: 29 AF XY: 0.00000277 AC XY: 1 AN XY: 361058

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000516

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 21

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

Labcorp Genetics (formerly Invitae), Labcorp

Oct 24, 2023

This sequence change replaces leucine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 22 of the GRIA3 protein (p.Leu22Ile). This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with GRIA3-related conditions. ClinVar contains an entry for this variant (Variation ID: 1422170). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	0.0058	T
BayesDel_noAF	Benign	-0.23
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Benign	0.073	T;T;T;T;T;.
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.78	.;T;T;T;.;T
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.27	T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.8	.;L;.;.;L;L
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.57	T
Sift4G	Benign	0.12	T;T;T;T;T;T
Polyphen		0.24, 0.53	.;B;.;.;B;P
Vest4		0.49
MutPred		0.45		Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);
MVP		0.79
ClinPred		0.51	D
GERP RS		4.8
Varity_R		0.29
gMVP		0.47

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: rs746285416; hg19: chrX-122318451;