5-178981682-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000843.4(GRM6):c.2609G>A(p.Gly870Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,750 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. G870G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GRM6 NM_000843.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.46

Genes affected

GRM6 (HGNC:4598): (glutamate metabotropic receptor 6) 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. Mutations in this gene result in congenital stationary night blindness type 1B. [provided by RefSeq, May 2018]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09915337).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRM6	NM_000843.4	c.2609G>A	p.Gly870Asp	missense_variant	11/11	ENST00000517717.3
ZNF454	XR_007058600.1	n.5644-8065C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRM6	ENST00000517717.3	c.2609G>A	p.Gly870Asp	missense_variant	11/11	5	NM_000843.4	P1
	ENST00000519491.1	n.305-8065C>T		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250860 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135642

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461750 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727190

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

Sep 13, 2022

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt GRM6 protein function. ClinVar contains an entry for this variant (Variation ID: 1393868). This variant has not been reported in the literature in individuals affected with GRM6-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 870 of the GRM6 protein (p.Gly870Asp). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.086
BayesDel_addAF	Benign	0.0082	T
BayesDel_noAF	Benign	-0.14
Cadd	Benign	20
Dann	Uncertain	0.99
DEOGEN2	Benign	0.15	T;T;T
Eigen	Benign	-0.55
Eigen_PC	Benign	-0.53
FATHMM_MKL	Benign	0.32	N
LIST_S2	Benign	0.72	T;.;.
M_CAP	Benign	0.078	D
MetaRNN	Benign	0.099	T;T;T
MetaSVM	Benign	-0.37	T
MutationAssessor	Benign	1.1	L;L;L
MutationTaster	Benign	0.98	N;N
PrimateAI	Benign	0.34	T
PROVEAN	Benign	-1.5	N;N;.
REVEL	Uncertain	0.35
Sift	Benign	0.065	T;T;.
Sift4G	Uncertain	0.024	D;D;.
Polyphen		0.012	B;B;B
Vest4		0.25
MutPred		0.18		Gain of solvent accessibility (P = 0.0354);Gain of solvent accessibility (P = 0.0354);Gain of solvent accessibility (P = 0.0354);
MVP		0.72
MPC		0.14
ClinPred		0.20	T
GERP RS		4.6
Varity_R		0.13
gMVP		0.26

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1290306808; hg19: chr5-178408683;