chr6-146399414-A-G

Position:

• chr6-146399414-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_001278064.2(GRM1):​c.2375A>G​(p.Tyr792Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GRM1 NM_001278064.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity no assertion criteria provided P:2 U:2
• Conservation: PhyloP100: 9.32

Genes affected

GRM1 (HGNC:4593): (glutamate metabotropic receptor 1) This gene encodes a metabotropic glutamate receptor that functions by activating phospholipase C. 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 canonical alpha isoform of the encoded protein is a disulfide-linked homodimer whose activity is mediated by a G-protein-coupled phosphatidylinositol-calcium second messenger system. This gene may be associated with many disease states, including schizophrenia, bipolar disorder, depression, and breast cancer. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, May 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), GRM1. . Gene score misZ 2.5817 (greater than the threshold 3.09). Trascript score misZ 3.6372 (greater than threshold 3.09). GenCC has associacion of gene with spinocerebellar ataxia 44, autosomal recessive spinocerebellar ataxia 13.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.91

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRM1	NM_001278064.2	c.2375A>G	p.Tyr792Cys	missense_variant	7/8	ENST00000282753.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRM1	ENST00000282753.6	c.2375A>G	p.Tyr792Cys	missense_variant	7/8	1	NM_001278064.2	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:2

Revision: no assertion criteria provided

Submissions by phenotype

Spinocerebellar ataxia 44 Pathogenic:2

Pathogenic, no assertion criteria provided	research	O&I group, Department of Genetics, University Medical Center of Groningen	Jul 22, 2021	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Nov 18, 2020	- -

not provided Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Uncertain significance, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	.;D;.;D;.
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	.;D;D;.;D
M_CAP	Pathogenic	0.41	D
MetaRNN	Pathogenic	0.91	D;D;D;D;D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	3.3	M;M;M;M;M
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.95	D
PROVEAN	Pathogenic	-8.6	D;D;D;D;D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	D;D;.;D;D
Vest4		0.87
MutPred		0.59		Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);
MVP		0.95
MPC		1.9
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.94
gMVP		0.97

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: rs1554308513; hg19: chr6-146720550; COSMIC: COSV51185896;