chr5-178989075-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PP3_ModeratePP5

The NM_000843.4(GRM6):ā€‹c.1214T>Cā€‹(p.Ile405Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000533 in 1,613,960 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: š‘“ 0.000026 ( 0 hom., cov: 32)
Exomes š‘“: 0.000056 ( 0 hom. )

Consequence

GRM6
NM_000843.4 missense

Scores

8
9
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:1

Conservation

PhyloP100: 9.20
Variant links:
Genes affected
GRM6 (HGNC:4598): (glutamate metabotropic receptor 6) 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 metabotropic glutamate receptors are a family of G protein-coupled receptors, that have been divided into 3 groups on the basis of sequence homology, putative signal transduction mechanisms, and pharmacologic properties. Group I includes GRM1 and GRM5 and these receptors have been shown to activate phospholipase C. Group II includes GRM2 and GRM3 while Group III includes GRM4, GRM6, GRM7 and GRM8. Group II and III receptors are linked to the inhibition of the cyclic AMP cascade but differ in their agonist selectivities. Mutations in this gene result in congenital stationary night blindness type 1B. [provided by RefSeq, May 2018]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.916
PP5
Variant 5-178989075-A-G is Pathogenic according to our data. Variant chr5-178989075-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 5847.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
GRM6NM_000843.4 linkuse as main transcriptc.1214T>C p.Ile405Thr missense_variant 7/11 ENST00000517717.3 NP_000834.2
ZNF454XR_007058600.1 linkuse as main transcriptn.5644-672A>G intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
GRM6ENST00000517717.3 linkuse as main transcriptc.1214T>C p.Ile405Thr missense_variant 7/115 NM_000843.4 ENSP00000430767 P1
ENST00000519491.1 linkuse as main transcriptn.305-672A>G intron_variant, non_coding_transcript_variant 3
GRM6ENST00000231188.9 linkuse as main transcriptc.1214T>C p.Ile405Thr missense_variant 6/102 ENSP00000231188 P1
GRM6ENST00000650031.1 linkuse as main transcriptc.1214T>C p.Ile405Thr missense_variant 8/12 ENSP00000497110 P1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152190
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000319
AC:
8
AN:
250528
Hom.:
0
AF XY:
0.0000295
AC XY:
4
AN XY:
135582
show subpopulations
Gnomad AFR exome
AF:
0.0000617
Gnomad AMR exome
AF:
0.00
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:
0.0000531
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000561
AC:
82
AN:
1461770
Hom.:
0
Cov.:
37
AF XY:
0.0000550
AC XY:
40
AN XY:
727178
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
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:
0.0000719
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152190
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74348
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000588
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000780
Hom.:
0
Bravo
AF:
0.0000756
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000349
AC:
3
ExAC
AF:
0.0000330
AC:
4
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:3Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:2Uncertain:1
Likely pathogenic, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Jun 13, 2017- -
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJun 30, 2023In 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. Experimental studies have shown that this missense change affects GRM6 function (PMID: 17405131). 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 GRM6 protein function. ClinVar contains an entry for this variant (Variation ID: 5847). This missense change has been observed in individual(s) with congenital stationary night blindness (PMID: 17405131). This variant is present in population databases (rs121434304, gnomAD 0.006%). This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 405 of the GRM6 protein (p.Ile405Thr). -
Likely pathogenic, criteria provided, single submitterclinical testingGeneDxJan 26, 2017The I405T variant in the GRM6 gene has been reported previously in association with autosomal recessive congenital stationary night blindness when present in the homozygous state (Zeitz et al., 2007). The I405T variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The I405T variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. In addition, this substitution occurs at a position that is conserved across species. Functional studies of the I405T variant demonstrate a transport defect of the GRM6 protein (Zeitz et al., 2007). The I405T variant is a strong candidate for a pathogenic variant, however the possibility it may be a rare benign variant cannot be excluded. -
Congenital stationary night blindness 1B Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMAug 01, 2007- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.36
BayesDel_addAF
Pathogenic
0.27
D
BayesDel_noAF
Pathogenic
0.34
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.65
D;D;D
Eigen
Uncertain
0.65
Eigen_PC
Uncertain
0.58
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D;.;.
M_CAP
Benign
0.040
D
MetaRNN
Pathogenic
0.92
D;D;D
MetaSVM
Uncertain
0.67
D
MutationAssessor
Pathogenic
2.9
M;M;M
MutationTaster
Benign
1.0
A;A
PrimateAI
Pathogenic
0.82
D
PROVEAN
Uncertain
-3.6
D;D;.
REVEL
Pathogenic
0.83
Sift
Uncertain
0.0040
D;D;.
Sift4G
Uncertain
0.053
T;T;.
Polyphen
0.86
P;P;P
Vest4
0.95
MVP
0.90
MPC
0.39
ClinPred
0.77
D
GERP RS
5.2
Varity_R
0.53
gMVP
0.50

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs121434304; hg19: chr5-178416076; API