6-146029543-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_001278064.2(GRM1):c.26T>C(p.Phe9Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,852 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: GRM1 NM_001278064.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.35

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, GRM1
• BP4: Computational evidence support a benign effect (MetaRNN=0.23882553).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GRM1	NM_001278064.2	c.26T>C	p.Phe9Ser	missense_variant	1/8	ENST00000282753.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GRM1	ENST00000282753.6	c.26T>C	p.Phe9Ser	missense_variant	1/8	1	NM_001278064.2	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251010 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135866

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: 0.00000274 AC: 4 AN: 1461852 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727230

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Dec 27, 2023

Variant summary: GRM1 c.26T>C (p.Phe9Ser) results in a non-conservative amino acid change in the encoded protein sequence. Two of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251010 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.26T>C in individuals affected with Autosomal Recessive Spinocerebellar Ataxia and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Benign	-0.042	T
BayesDel_noAF	Benign	-0.22
Cadd	Benign	19
Dann	Uncertain	0.98
Eigen	Benign	-0.098
Eigen_PC	Benign	0.040
FATHMM_MKL	Benign	0.63	D
M_CAP	Benign	0.027	D
MetaRNN	Benign	0.24	T;T;T;T;T
MetaSVM	Benign	-0.30	T
MutationAssessor	Benign	1.2	L;L;L;L;L
MutationTaster	Benign	0.75	D;D;D;D;D;D
PrimateAI	Benign	0.48	T
PROVEAN	Benign	-0.30	N;N;N;N;N
REVEL	Uncertain	0.33
Sift	Benign	0.099	T;T;T;T;T
Sift4G	Benign	0.36	T;T;T;T;T
Polyphen		0.0	B;B;.;B;B
Vest4		0.27
MutPred		0.58		Loss of stability (P = 0.0322);Loss of stability (P = 0.0322);Loss of stability (P = 0.0322);Loss of stability (P = 0.0322);Loss of stability (P = 0.0322);
MVP		0.47
MPC		1.2
ClinPred		0.28	T
GERP RS		5.4
Varity_R		0.10
gMVP		0.71

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs1339024978; hg19: chr6-146350679;