5-178981761-G-C

Position:

• chr5-178981761-G-C

Variant summary

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

The NM_000843.4(GRM6):​c.2530C>G​(p.Leu844Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L844I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GRM6 NM_000843.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.315

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=0.2615992).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRM6	NM_000843.4	c.2530C>G	p.Leu844Val	missense_variant	11/11	ENST00000517717.3
ZNF454	XR_007058600.1	n.5644-7986G>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRM6	ENST00000517717.3	c.2530C>G	p.Leu844Val	missense_variant	11/11	5	NM_000843.4	P1
	ENST00000519491.1	n.305-7986G>C		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

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

Labcorp Genetics (formerly Invitae), Labcorp

Dec 20, 2019

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with GRM6-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with valine at codon 844 of the GRM6 protein (p.Leu844Val). The leucine residue is moderately conserved and there is a small physicochemical difference between leucine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Uncertain	0.016	T
BayesDel_noAF	Benign	-0.21
CADD	Benign	17
DANN	Benign	0.97
DEOGEN2	Benign	0.17	T;T;T
Eigen	Benign	-0.49
Eigen_PC	Benign	-0.37
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.87	D;.;.
M_CAP	Benign	0.041	D
MetaRNN	Benign	0.26	T;T;T
MetaSVM	Benign	-0.32	T
MutationAssessor	Benign	0.69	N;N;N
MutationTaster	Benign	0.96	D;D
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-0.45	N;N;.
REVEL	Benign	0.19
Sift	Benign	0.30	T;T;.
Sift4G	Benign	0.29	T;T;.
Polyphen		0.11	B;B;B
Vest4		0.076
MutPred		0.71		Gain of MoRF binding (P = 0.0971);Gain of MoRF binding (P = 0.0971);Gain of MoRF binding (P = 0.0971);
MVP		0.81
MPC		0.11
ClinPred		0.12	T
GERP RS		2.3
Varity_R		0.071
gMVP		0.21

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: rs1760399415; hg19: chr5-178408762;