rs766935302

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000158.4(GBE1):​c.1909C>T​(p.Arg637*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000304 in 1,610,418 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000032 ( 0 hom. )

Consequence

GBE1
NM_000158.4 stop_gained

Scores

2
2
3

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 1.51

Publications

2 publications found
Variant links:
Genes affected
GBE1 (HGNC:4180): (1,4-alpha-glucan branching enzyme 1) The protein encoded by this gene is a glycogen branching enzyme that catalyzes the transfer of alpha-1,4-linked glucosyl units from the outer end of a glycogen chain to an alpha-1,6 position on the same or a neighboring glycogen chain. Branching of the chains is essential to increase the solubility of the glycogen molecule and, consequently, in reducing the osmotic pressure within cells. Highest level of this enzyme are found in liver and muscle. Mutations in this gene are associated with glycogen storage disease IV (also known as Andersen's disease). [provided by RefSeq, Jul 2008]
GBE1 Gene-Disease associations (from GenCC):
  • glycogen storage disease due to glycogen branching enzyme deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Laboratory for Molecular Medicine, Ambry Genetics, G2P, ClinGen
  • adult polyglucosan body disease
    Inheritance: AR Classification: MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 3-81535220-G-A is Pathogenic according to our data. Variant chr3-81535220-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 346785.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
GBE1NM_000158.4 linkc.1909C>T p.Arg637* stop_gained Exon 14 of 16 ENST00000429644.7 NP_000149.4 Q04446Q59ET0
GBE1XR_007095662.1 linkn.2037C>T non_coding_transcript_exon_variant Exon 14 of 15

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GBE1ENST00000429644.7 linkc.1909C>T p.Arg637* stop_gained Exon 14 of 16 1 NM_000158.4 ENSP00000410833.2 Q04446
GBE1ENST00000489715.1 linkc.1786C>T p.Arg596* stop_gained Exon 14 of 16 2 ENSP00000419638.1 E9PGM4
GBE1ENST00000484687.1 linkn.310C>T non_coding_transcript_exon_variant Exon 3 of 3 2

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151508
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.0000284
AC:
7
AN:
246842
AF XY:
0.0000299
show subpopulations
Gnomad AFR exome
AF:
0.0000651
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:
0.0000535
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000322
AC:
47
AN:
1458910
Hom.:
0
Cov.:
31
AF XY:
0.0000289
AC XY:
21
AN XY:
725718
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33334
American (AMR)
AF:
0.00
AC:
0
AN:
44416
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26060
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39590
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85906
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53208
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5746
European-Non Finnish (NFE)
AF:
0.0000414
AC:
46
AN:
1110430
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60220
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.447
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000132
AC:
2
AN:
151508
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
73966
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41286
American (AMR)
AF:
0.00
AC:
0
AN:
15156
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5144
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4806
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10480
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67860
Other (OTH)
AF:
0.00
AC:
0
AN:
2082
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000688
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000331
AC:
4
EpiCase
AF:
0.000109
EpiControl
AF:
0.000119

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Glycogen storage disease, type IV Pathogenic:3
Sep 16, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jul 24, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 27, 2022
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

The p.Arg637Ter variant in GBE1 has been reported in 4 individuals with glycogen storage disease type IV (GSD IV) (PMID: 15452297, 15520786, 19438752, 31747834) and has been identified in 0.007% (1/15366) of African/African-American chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs766935302). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. Of the 4 affected individuals, 1 of those was a homozygote and 1 was a compound heterozygote that carried a reported variant of uncertain significance in trans, which increases the likelihood that the p.Arg637Ter variant is pathogenic (PMID: 19438752, 31747834). This variant has also been reported in ClinVar (Variation ID#: 346785) and has been interpreted as likely pathogenic or pathogenic by Illumina Clinical Services Laboratory, Invitae and Natera. This nonsense variant leads to a premature termination codon at position 637, which is predicted to lead to a truncated or absent protein. Loss of function of the GBE1 gene is an established disease mechanism in autosomal recessive GSD IV. The phenotype of individuals homozygous or compound heterozygous for this variant is highly specific for GSD IV based on strict biochemical investigations consistent with disease (PMID: 15452297, 19438752). In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive GSD IV. ACMG/AMP Criteria applied: PVS1, PM2_supporting, PM3_supporting, PP4 (Richards 2015). -

GBE1-related disorder Pathogenic:1
Apr 28, 2017
Illumina Laboratory Services, Illumina
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The GBE1 c.1909C>T (p.Arg637Ter) variant is a stop-gained variant that has been reported in three studies, in which it is found in a total of three individuals with the most severe form of glycogen storage disorder type IV, including in one in a homozygous state and in two in a compound heterozygous state (Bruno et al. 2004; Janecke et al. 2004; Jimenez-Mallebrera et al. 2009). The p.Arg637Ter variant was absent from 120 control chromosomes but reported at a frequency of 0.00005 in the European (non-Finnish) population of the Exome Aggregation Consortium. Functional studies in both individual fibroblasts and muscle tissue demonstrated that the variant resulted in less than five percent of glycogen branching enzyme activity compared to wild type (Bruno et al. 2004; Jimenez-Mallebrera et al. 2009). Due to the potential impact of stop-gained variants and the supporting evidence, the p.Arg637Ter variant is considered to be pathogenic for GBE1-related disorders. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Glycogen storage disease, type IV;C1856301:Glycogen storage disease IV, classic hepatic Pathogenic:1
Apr 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg637*) in the GBE1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GBE1 are known to be pathogenic (PMID: 15452297, 20058079). This variant is present in population databases (rs766935302, gnomAD 0.007%). This premature translational stop signal has been observed in individual(s) with glycogen storage disease (PMID: 15452297, 15520786, 17915577). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 346785). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.44
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
37
DANN
Uncertain
0.99
Eigen
Benign
0.17
Eigen_PC
Benign
-0.050
FATHMM_MKL
Uncertain
0.85
D
PhyloP100
1.5
Vest4
0.92
GERP RS
-3.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=1/199
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.23
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.23
Position offset: -25

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs766935302; hg19: chr3-81584371; COSMIC: COSV70100924; API