chr5-151822682-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2PM5PP3

The NM_000171.4(GLRA1):​c.1341C>A​(p.His447Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000343 in 1,459,412 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. H447N) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

GLRA1
NM_000171.4 missense

Scores

1
13
4

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.34

Publications

0 publications found
Variant links:
Genes affected
GLRA1 (HGNC:4326): (glycine receptor alpha 1) The protein encoded by this gene is a subunit of a pentameric inhibitory glycine receptor, which mediates postsynaptic inhibition in the central nervous system. Defects in this gene are a cause of startle disease (STHE), also known as hereditary hyperekplexia or congenital stiff-person syndrome. Multiple transcript variants encoding different isoforms have been found. [provided by RefSeq, Dec 2015]
GLRA1 Gene-Disease associations (from GenCC):
  • hyperekplexia 1
    Inheritance: AR, AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
  • hereditary hyperekplexia
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr5-151822684-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1379370.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.78

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GLRA1NM_000171.4 linkc.1341C>A p.His447Gln missense_variant Exon 9 of 9 ENST00000274576.9 NP_000162.2 P23415-2
GLRA1NM_001146040.2 linkc.1365C>A p.His455Gln missense_variant Exon 9 of 9 NP_001139512.1 P23415-1
GLRA1NM_001292000.2 linkc.1092C>A p.His364Gln missense_variant Exon 8 of 8 NP_001278929.1 Q14C71
GLRA1XM_047417105.1 linkc.1389C>A p.His463Gln missense_variant Exon 9 of 9 XP_047273061.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLRA1ENST00000274576.9 linkc.1341C>A p.His447Gln missense_variant Exon 9 of 9 1 NM_000171.4 ENSP00000274576.5 P23415-2
GLRA1ENST00000455880.2 linkc.1365C>A p.His455Gln missense_variant Exon 9 of 9 1 ENSP00000411593.2 P23415-1
GLRA1ENST00000462581.6 linkn.*1099C>A non_coding_transcript_exon_variant Exon 8 of 8 1 ENSP00000430595.1 E5RJ70
GLRA1ENST00000462581.6 linkn.*1099C>A 3_prime_UTR_variant Exon 8 of 8 1 ENSP00000430595.1 E5RJ70

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251252
AF XY:
0.0000147
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000343
AC:
5
AN:
1459412
Hom.:
0
Cov.:
30
AF XY:
0.00000275
AC XY:
2
AN XY:
726224
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33418
American (AMR)
AF:
0.0000224
AC:
1
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26110
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86192
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1109784
Other (OTH)
AF:
0.00
AC:
0
AN:
60338
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.395
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
31
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Hereditary hyperekplexia Uncertain:1
Nov 29, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. 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 GLRA1 protein function. This variant has not been reported in the literature in individuals affected with GLRA1-related conditions. This variant is present in population databases (rs773707878, gnomAD 0.003%). This sequence change replaces histidine, which is basic and polar, with glutamine, which is neutral and polar, at codon 447 of the GLRA1 protein (p.His447Gln). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.086
BayesDel_addAF
Uncertain
0.022
T
BayesDel_noAF
Benign
-0.12
CADD
Uncertain
25
DANN
Uncertain
0.99
Eigen
Uncertain
0.61
Eigen_PC
Uncertain
0.55
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Uncertain
0.87
D;D
M_CAP
Uncertain
0.090
D
MetaRNN
Pathogenic
0.78
D;D
MetaSVM
Uncertain
0.14
D
MutationAssessor
Benign
2.0
.;M
PhyloP100
6.3
PrimateAI
Uncertain
0.73
T
PROVEAN
Uncertain
-2.6
D;D
REVEL
Uncertain
0.43
Sift
Uncertain
0.018
D;D
Sift4G
Uncertain
0.059
T;T
Polyphen
1.0
D;D
Vest4
0.67
MutPred
0.36
.;Loss of catalytic residue at N456 (P = 0.1325);
MVP
0.82
MPC
0.12
ClinPred
0.77
D
GERP RS
3.9
Varity_R
0.51
gMVP
0.73
Mutation Taster
=8/92
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

Publications

Other links and lift over

dbSNP: rs773707878; hg19: chr5-151202243; API