rs776919102

chr5-151851581-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM1 PP3

The NM_000171.4(GLRA1):c.721C>T(p.Arg241Trp) variant causes a missense change. The variant allele was found at a frequency of 0.00000821 in 1,461,198 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. R241Q) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: GLRA1 NM_000171.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.42

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a topological_domain Extracellular (size 221) in uniprot entity GLRA1_HUMAN there are 20 pathogenic changes around while only 5 benign (80%) in NM_000171.4
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.825

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GLRA1	NM_000171.4	c.721C>T	p.Arg241Trp	missense_variant	7/9	ENST00000274576.9
GLRA1	NM_001146040.2	c.721C>T	p.Arg241Trp	missense_variant	7/9
GLRA1	NM_001292000.2	c.472C>T	p.Arg158Trp	missense_variant	6/8
GLRA1	XM_047417105.1	c.769C>T	p.Arg257Trp	missense_variant	7/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GLRA1	ENST00000274576.9	c.721C>T	p.Arg241Trp	missense_variant	7/9	1	NM_000171.4	P4
GLRA1	ENST00000455880.2	c.721C>T	p.Arg241Trp	missense_variant	7/9	1		A1
GLRA1	ENST00000471351.2	n.1004C>T		non_coding_transcript_exon_variant	7/8	1
GLRA1	ENST00000462581.6	c.*479C>T		3_prime_UTR_variant, NMD_transcript_variant	6/8	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251376 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135860

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000821 AC: 12 AN: 1461198 Hom.: 0 Cov.: 31 AF XY: 0.00000825 AC XY: 6 AN XY: 726972

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: 0.0000580

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000247 AC: 3

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary hyperekplexia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 21, 2023

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 241 of the GLRA1 protein (p.Arg241Trp). This variant is present in population databases (rs776919102, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with GLRA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 575323). 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. 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	Uncertain	0.35
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Pathogenic	0.14
Cadd	Pathogenic	34
Dann	Pathogenic	1.0
Eigen	Pathogenic	0.69
Eigen_PC	Pathogenic	0.66
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.82	D;D
MetaSVM	Uncertain	0.30	D
MutationAssessor	Benign	2.0	M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Uncertain	-3.4	D;D
REVEL	Uncertain	0.60
Sift	Uncertain	0.015	D;D
Sift4G	Uncertain	0.017	D;D
Polyphen		1.0	D;D
Vest4		0.74
MutPred		0.54		Loss of methylation at R241 (P = 0.0499);Loss of methylation at R241 (P = 0.0499);
MVP		0.89
MPC		2.1
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.66
gMVP		0.86

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

Other links and lift over

dbSNP: rs776919102; hg19: chr5-151231142; COSMIC: COSV51010950; COSMIC: COSV51010950;