NM_007327.4:c.649C>T

Variant names:

• chr9-137149087-C-T
• rs200777850
• NM_007327.4:c.649C>T

Variant summary

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

The NM_007327.4(GRIN1):​c.649C>T​(p.Arg217Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,458,996 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R217Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GRIN1 NM_007327.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 2.07
• Publications: 8 publications found

Genes affected

GRIN1 (HGNC:4584): (glutamate ionotropic receptor NMDA type subunit 1) The protein encoded by this gene is a critical subunit of N-methyl-D-aspartate receptors, members of the glutamate receptor channel superfamily which are heteromeric protein complexes with multiple subunits arranged to form a ligand-gated ion channel. These subunits play a key role in the plasticity of synapses, which is believed to underlie memory and learning. Cell-specific factors are thought to control expression of different isoforms, possibly contributing to the functional diversity of the subunits. Alternatively spliced transcript variants have been described. [provided by RefSeq, Jul 2008]

GRIN1 Gene-Disease associations (from GenCC):

• neurodevelopmental disorder with or without hyperkinetic movements and seizures, autosomal dominant

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• complex neurodevelopmental disorder

  Inheritance: AR, AD Classification: DEFINITIVE Submitted by: ClinGen
• neurodevelopmental disorder with or without hyperkinetic movements and seizures, autosomal recessive

  Inheritance: AR Classification: DEFINITIVE, MODERATE Submitted by: G2P, Ambry Genetics
• developmental and epileptic encephalopathy 101

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• autosomal dominant non-syndromic intellectual disability

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

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, 0.901

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GRIN1	NM_007327.4	c.649C>T	p.Arg217Trp	missense_variant	Exon 4 of 20	ENST00000371561.8	NP_015566.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GRIN1	ENST00000371561.8	c.649C>T	p.Arg217Trp	missense_variant	Exon 4 of 20	1	NM_007327.4	ENSP00000360616.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458996 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 725694

African (AFR) AF: 0.00 AC: 0 AN: 33412

American (AMR) AF: 0.00 AC: 0 AN: 44558

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26090

East Asian (EAS) AF: 0.00 AC: 0 AN: 39618

South Asian (SAS) AF: 0.0000117 AC: 1 AN: 85778

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53214

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 9.01e-7 AC: 1 AN: 1110320

Other (OTH) AF: 0.00 AC: 0 AN: 60242

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

NEURODEVELOPMENTAL DISORDER WITH HYPERKINETIC MOVEMENTS WITH OR WITHOUT SEIZURES, AUTOSOMAL RECESSIVE Pathogenic:1

Mar 28, 2022

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Neurodevelopmental disorder with or without hyperkinetic movements and seizures, autosomal dominant Uncertain:1

Feb 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 217 of the GRIN1 protein (p.Arg217Trp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with autosomal recessive GRIN1-related conditions (PMID: 27164704). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 487505). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on GRIN1 protein function. Experimental studies have shown that this missense change affects GRIN1 function (PMID: 27164704, 34884460). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.91	D;.;.;T;.;.;.
Eigen	Uncertain	0.51
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D
M_CAP	Benign	0.073	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D;D
MetaSVM	Benign	-0.71	T
MutationAssessor	Benign	1.9	L;L;.;.;.;L;.
PhyloP100		2.1
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-6.0	D;D;D;D;D;D;D
REVEL	Uncertain	0.52
Sift	Uncertain	0.0010	D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D
Polyphen		1.0	D;D;.;.;.;D;.
Vest4		0.95
MutPred		0.76		Gain of catalytic residue at R217 (P = 0.0286);Gain of catalytic residue at R217 (P = 0.0286);.;.;.;Gain of catalytic residue at R217 (P = 0.0286);.;
MVP		0.91
MPC		2.6
ClinPred		0.99	D
GERP RS		3.8
Varity_R		0.57
gMVP		0.97
Mutation Taster		=0/100	disease causing (ClinVar)

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: rs200777850; hg19: chr9-140043539;