chr6-146399101-G-T

Variant names:

• chr6-146399101-G-T
• rs965990929
• NM_001278064.2:c.2062G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001278064.2(GRM1):​c.2062G>T​(p.Gly688Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,078 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G688S) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: GRM1 NM_001278064.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.19
• Publications: 0 publications found

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]

GRM1 Gene-Disease associations (from GenCC):

• spinocerebellar ataxia 44

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• autosomal recessive spinocerebellar ataxia 13

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.899

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001278064.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRM1	NM_001278064.2	MANE Select	c.2062G>T	p.Gly688Cys	missense	Exon 7 of 8	NP_001264993.1
	GRM1	NM_001278067.1		c.2062G>T	p.Gly688Cys	missense	Exon 7 of 8	NP_001264996.1
	GRM1	NM_001278065.2		c.2062G>T	p.Gly688Cys	missense	Exon 8 of 10	NP_001264994.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRM1	ENST00000282753.6	TSL:1 MANE Select	c.2062G>T	p.Gly688Cys	missense	Exon 7 of 8	ENSP00000282753.1
	GRM1	ENST00000355289.8	TSL:1	c.2062G>T	p.Gly688Cys	missense	Exon 7 of 8	ENSP00000347437.4
	GRM1	ENST00000492807.6	TSL:1	c.2062G>T	p.Gly688Cys	missense	Exon 8 of 10	ENSP00000424095.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152078 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 34

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152078 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74292

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000241 AC: 1 AN: 41410

American (AMR) AF: 0.00 AC: 0 AN: 15258

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5176

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68002

Other (OTH) AF: 0.00 AC: 0 AN: 2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.82	D
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.37	D
MetaRNN	Pathogenic	0.90	D
MetaSVM	Pathogenic	0.80	D
MutationAssessor	Uncertain	2.9	M
PhyloP100		8.2
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-7.9	D
REVEL	Pathogenic	0.86
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.86
MutPred		0.53		Loss of disorder (P = 0.0516)
MVP		0.90
MPC		1.8
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.89
gMVP		0.94
Mutation Taster		=36/64	disease causing

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

Other links and lift over

dbSNP: rs965990929; hg19: chr6-146720237;