rs121918418

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_StrongPP5_Very_Strong

The NM_000171.4(GLRA1):​c.971C>A​(p.Ser324*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 1,614,016 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 Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

GLRA1
NM_000171.4 stop_gained

Scores

5
1
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 9.72
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.281 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
PP5
Variant 5-151829009-G-T is Pathogenic according to our data. Variant chr5-151829009-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 16073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GLRA1NM_000171.4 linkc.971C>A p.Ser324* stop_gained Exon 8 of 9 ENST00000274576.9 NP_000162.2 P23415-2
GLRA1NM_001146040.2 linkc.971C>A p.Ser324* stop_gained Exon 8 of 9 NP_001139512.1 P23415-1
GLRA1NM_001292000.2 linkc.722C>A p.Ser241* stop_gained Exon 7 of 8 NP_001278929.1 Q14C71
GLRA1XM_047417105.1 linkc.1019C>A p.Ser340* stop_gained Exon 8 of 9 XP_047273061.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLRA1ENST00000274576.9 linkc.971C>A p.Ser324* stop_gained Exon 8 of 9 1 NM_000171.4 ENSP00000274576.5 P23415-2
GLRA1ENST00000455880.2 linkc.971C>A p.Ser324* stop_gained Exon 8 of 9 1 ENSP00000411593.2 P23415-1
GLRA1ENST00000462581.6 linkn.*729C>A non_coding_transcript_exon_variant Exon 7 of 8 1 ENSP00000430595.1 E5RJ70
GLRA1ENST00000462581.6 linkn.*729C>A 3_prime_UTR_variant Exon 7 of 8 1 ENSP00000430595.1 E5RJ70

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152246
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000137
AC:
20
AN:
1461770
Hom.:
0
Cov.:
31
AF XY:
0.0000138
AC XY:
10
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:
0.0000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152246
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74374
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:
0.0000294
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000557
Hom.:
0
Bravo
AF:
0.0000151
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hyperekplexia 1 Pathogenic:1
May 29, 2007
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

not provided Pathogenic:1
Oct 12, 2018
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The S324X nonsense variant in the GLRA1 gene has been reported previously (using S296X using alternative nomenclature) as a de novo change in an individual with hyperekplexia (Bellini et al., 2007). Functional studies demonstrated that S324X impairs protein function via a dominant negative effect (Bellini et al., 20017). This variant is not observed in large population cohorts (Lek et al., 2016). We interpret this variant as pathogenic. -

Hereditary hyperekplexia Pathogenic:1
Mar 01, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Experimental studies have shown that this premature translational stop signal affects GLRA1 function (PMID: 17536053). This sequence change creates a premature translational stop signal (p.Ser324*) in the GLRA1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 126 amino acid(s) of the GLRA1 protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with hyperekplexia (PMID: 17536053). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 16073). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.66
CADD
Pathogenic
45
DANN
Uncertain
1.0
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.95
FATHMM_MKL
Pathogenic
0.99
D
Vest4
0.74
GERP RS
5.1

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

LitVar

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

Other links and lift over

dbSNP: rs121918418; hg19: chr5-151208570; API