NM_000171.4:c.1339C>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3PP5

The NM_000171.4(GLRA1):​c.1339C>A​(p.His447Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,611,936 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H447R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

GLRA1
NM_000171.4 missense

Scores

3
12
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 9.77

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 2 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.8
PP5
Variant 5-151822684-G-T is Pathogenic according to our data. 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 submissions are: {Uncertain_significance=2, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GLRA1NM_000171.4 linkc.1339C>A p.His447Asn missense_variant Exon 9 of 9 ENST00000274576.9 NP_000162.2 P23415-2
GLRA1NM_001146040.2 linkc.1363C>A p.His455Asn missense_variant Exon 9 of 9 NP_001139512.1 P23415-1
GLRA1NM_001292000.2 linkc.1090C>A p.His364Asn missense_variant Exon 8 of 8 NP_001278929.1 Q14C71
GLRA1XM_047417105.1 linkc.1387C>A p.His463Asn 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.1339C>A p.His447Asn missense_variant Exon 9 of 9 1 NM_000171.4 ENSP00000274576.5 P23415-2
GLRA1ENST00000455880.2 linkc.1363C>A p.His455Asn missense_variant Exon 9 of 9 1 ENSP00000411593.2 P23415-1
GLRA1ENST00000462581.6 linkn.*1097C>A non_coding_transcript_exon_variant Exon 8 of 8 1 ENSP00000430595.1 E5RJ70
GLRA1ENST00000462581.6 linkn.*1097C>A 3_prime_UTR_variant Exon 8 of 8 1 ENSP00000430595.1 E5RJ70

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152120
Hom.:
0
Cov.:
31
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251242
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000343
AC:
5
AN:
1459816
Hom.:
0
Cov.:
30
AF XY:
0.00000688
AC XY:
5
AN XY:
726406
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33438
American (AMR)
AF:
0.00
AC:
0
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26118
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86170
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1110194
Other (OTH)
AF:
0.00
AC:
0
AN:
60332
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.545
Heterozygous variant carriers
0
1
1
2
2
3
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
AF:
0.00000657
AC:
1
AN:
152120
Hom.:
0
Cov.:
31
AF XY:
0.0000135
AC XY:
1
AN XY:
74294
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41402
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.725
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.00000756
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Seizure Pathogenic:1
May 22, 2024
Génétique des Maladies du Développement, Hospices Civils de Lyon
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Aug 01, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1339C>A (p.H447N) alteration is located in exon 9 (coding exon 9) of the GLRA1 gene. This alteration results from a C to A substitution at nucleotide position 1339, causing the histidine (H) at amino acid position 447 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hereditary hyperekplexia Uncertain:1
Apr 23, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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) performed at Invitae indicates that this missense variant is not expected to disrupt GLRA1 protein function. This sequence change replaces histidine with asparagine at codon 447 of the GLRA1 protein (p.His447Asn). The histidine residue is moderately conserved and there is a small physicochemical difference between histidine and asparagine. This variant is present in population databases (rs146481873, ExAC 0.002%). This variant has not been reported in the literature in individuals with GLRA1-related conditions. 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
Benign
0.071
BayesDel_addAF
Uncertain
0.075
D
BayesDel_noAF
Benign
-0.13
CADD
Pathogenic
27
DANN
Uncertain
0.99
Eigen
Pathogenic
0.77
Eigen_PC
Pathogenic
0.75
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.90
D;D
M_CAP
Uncertain
0.10
D
MetaRNN
Pathogenic
0.80
D;D
MetaSVM
Uncertain
0.15
D
MutationAssessor
Uncertain
2.3
.;M
PhyloP100
9.8
PrimateAI
Uncertain
0.75
T
PROVEAN
Uncertain
-2.5
N;N
REVEL
Uncertain
0.38
Sift
Uncertain
0.0020
D;D
Sift4G
Uncertain
0.0080
D;D
Polyphen
1.0
D;D
Vest4
0.71
MVP
0.86
MPC
0.078
ClinPred
0.95
D
GERP RS
4.7
Varity_R
0.56
gMVP
0.72
Mutation Taster
=33/67
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: rs146481873; hg19: chr5-151202245; API