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
Consequence
NM_000158.4 stop_gained
Scores
Clinical Significance
Conservation
Publications
- glycogen storage disease due to glycogen branching enzyme deficiencyInheritance: 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 diseaseInheritance: AR Classification: MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| GBE1 | ENST00000429644.7 | c.1909C>T | p.Arg637* | stop_gained | Exon 14 of 16 | 1 | NM_000158.4 | ENSP00000410833.2 | ||
| GBE1 | ENST00000489715.1 | c.1786C>T | p.Arg596* | stop_gained | Exon 14 of 16 | 2 | ENSP00000419638.1 | |||
| GBE1 | ENST00000484687.1 | n.310C>T | non_coding_transcript_exon_variant | Exon 3 of 3 | 2 |
Frequencies
GnomAD3 genomes AF: 0.0000132 AC: 2AN: 151508Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000284 AC: 7AN: 246842 AF XY: 0.0000299 show subpopulations
GnomAD4 exome AF: 0.0000322 AC: 47AN: 1458910Hom.: 0 Cov.: 31 AF XY: 0.0000289 AC XY: 21AN XY: 725718 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000132 AC: 2AN: 151508Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 73966 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Glycogen storage disease, type IV Pathogenic:3
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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
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
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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at