Genetic Variant GRM8:p.Gly726Arg (chr7-126533206-C-T) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_000845.3(GRM8):c.2176G>A(p.Gly726Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000315 in 1,461,492 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 (★).

Frequency

Genomes: not found (cov: 30)

Exomes 𝑓: 0.000031 ( 0 hom. )

Consequence

GRM8
NM_000845.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.91

Variant links:

Genes affected

GRM8 (HGNC:4600): (glutamate metabotropic receptor 8) L-glutamate is the major excitatory neurotransmitter in the central nervous system and activates both ionotropic and metabotropic glutamate receptors. Glutamatergic neurotransmission is involved in most aspects of normal brain function and can be perturbed in many neuropathologic conditions. The metabotropic glutamate receptors are a family of G protein-coupled receptors, that have been divided into 3 groups on the basis of sequence homology, putative signal transduction mechanisms, and pharmacologic properties. Group I includes GRM1 and GRM5 and these receptors have been shown to activate phospholipase C. Group II includes GRM2 and GRM3 while Group III includes GRM4, GRM6, GRM7 and GRM8. Group II and III receptors are linked to the inhibition of the cyclic AMP cascade but differ in their agonist selectivities. Alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Jul 2008]

GRM8 links:

LOC101928357 (HGNC:):

LOC101928357 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.771

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GRM8	NM_000845.3 link	c.2176G>A	p.Gly726Arg	missense_variant	Exon 9 of 11	ENST00000339582.7	NP_000836.2	O00222-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GRM8	ENST00000339582.7 link	c.2176G>A	p.Gly726Arg	missense_variant	Exon 9 of 11	5	NM_000845.3	ENSP00000344173.2		O00222-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000160

AC:

AN:

250288

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135252

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000869

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:

0.00000885

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000315

AC:

AN:

1461492

Hom.:

Cov.:

AF XY:

0.0000358

AC XY:

AN XY:

727034

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000387

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000658

Hom.:

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Nov 11, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2176G>A (p.G726R) alteration is located in exon 9 (coding exon 8) of the GRM8 gene. This alteration results from a G to A substitution at nucleotide position 2176, causing the glycine (G) at amino acid position 726 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Pathogenic

0.14

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Benign

0.28

T;.;.

Eigen

Uncertain

0.39

Eigen_PC

Uncertain

0.51

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.90

D;.;D

M_CAP

Uncertain

0.16

MetaRNN

Pathogenic

0.77

D;D;D

MetaSVM

Uncertain

0.31

MutationAssessor

Benign

1.1

L;L;.

PrimateAI

Pathogenic

0.81

PROVEAN

Benign

-1.1

N;N;.

REVEL

Uncertain

0.62

Sift

Uncertain

0.015

D;D;.

Sift4G

Uncertain

0.041

D;D;T

Polyphen

0.022

B;D;.

Vest4

0.68

MutPred

0.40

Gain of solvent accessibility (P = 0.0456);Gain of solvent accessibility (P = 0.0456);.;

MVP

0.63

MPC

0.85

ClinPred

0.60

GERP RS

5.6

Varity_R

0.36

gMVP

0.86

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over