NM_001278064.2:c.2660+2T>G

Variant names:

• chr6-146399701-T-G
• rs211694393
• NM_001278064.2:c.2660+2T>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_001278064.2(GRM1):​c.2660+2T>G variant causes a splice donor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GRM1 NM_001278064.2 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.67
• Publications: 3 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: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

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.2660+2T>G		splice_donor intron	N/A	NP_001264993.1
	GRM1	NM_001278067.1		c.2660+2T>G		splice_donor intron	N/A	NP_001264996.1
	GRM1	NM_001278065.2		c.2660+2T>G		splice_donor intron	N/A	NP_001264994.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRM1	ENST00000282753.6	TSL:1 MANE Select	c.2660+2T>G		splice_donor intron	N/A	ENSP00000282753.1
	GRM1	ENST00000355289.8	TSL:1	c.2660+2T>G		splice_donor intron	N/A	ENSP00000347437.4
	GRM1	ENST00000492807.6	TSL:1	c.2660+2T>G		splice_donor intron	N/A	ENSP00000424095.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	32
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		7.7
GERP RS		5.7
Mutation Taster		=1/99	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.96		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.96		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs211694393; hg19: chr6-146720837;