rs606231368

Positions:

• chr17-42907558-G-GTA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000151.4(G6PC1):​c.379_380dupTA​(p.Tyr128fs) variant causes a frameshift change. The variant allele was found at a frequency of 0.000026 in 1,613,922 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000027 (0 hom.)
• Consequence: G6PC1 NM_000151.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:14 O:1
• Conservation: PhyloP100: 6.05

Genes affected

G6PC1 (HGNC:4056): (glucose-6-phosphatase catalytic subunit 1) Glucose-6-phosphatase (G6Pase) is a multi-subunit integral membrane protein of the endoplasmic reticulum that is composed of a catalytic subunit and transporters for G6P, inorganic phosphate, and glucose. This gene (G6PC) is one of the three glucose-6-phosphatase catalytic-subunit-encoding genes in human: G6PC, G6PC2 and G6PC3. Glucose-6-phosphatase catalyzes the hydrolysis of D-glucose 6-phosphate to D-glucose and orthophosphate and is a key enzyme in glucose homeostasis, functioning in gluconeogenesis and glycogenolysis. Mutations in this gene cause glycogen storage disease type I (GSD1). This disease, also known as von Gierke disease, is a metabolic disorder characterized by severe hypoglycemia associated with the accumulation of glycogen and fat in the liver and kidneys.[provided by RefSeq, Feb 2011]

ACMG classification

Verdict is Pathogenic. Variant got 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 17-42907558-G-GTA is Pathogenic according to our data. Variant chr17-42907558-G-GTA is described in ClinVar as [Pathogenic]. Clinvar id is 11997.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
G6PC1	NM_000151.4	c.379_380dupTA	p.Tyr128fs	frameshift_variant	3/5	ENST00000253801.7	NP_000142.2
G6PC1	NM_001270397.2	c.341-39_341-38dupTA		intron_variant			NP_001257326.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
G6PC1	ENST00000253801.7	c.379_380dupTA	p.Tyr128fs	frameshift_variant	3/5	1	NM_000151.4	ENSP00000253801.1
G6PC1	ENST00000585489.1	c.379_380dupTA	p.Tyr128fs	frameshift_variant	3/4	5		ENSP00000466202.1
G6PC1	ENST00000592383.5	c.341-39_341-38dupTA		intron_variant		2		ENSP00000465958.1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152170 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

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: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000107 AC: 27 AN: 251208 Hom.: 0 AF XY: 0.0000958 AC XY: 13 AN XY: 135758

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000781

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000267 AC: 39 AN: 1461752 Hom.: 0 Cov.: 31 AF XY: 0.0000289 AC XY: 21 AN XY: 727176

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000805

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: 0.00

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152170 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74326

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000718

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:14 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Glycogen storage disease due to glucose-6-phosphatase deficiency type IA Pathogenic:10 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jun 17, 2020	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Oct 01, 1995	- -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Dec 13, 2019	NM_000151.3(G6PC):c.379_380dupTA(Y128Tfs*3) is classified as pathogenic in the context of glycogen storage disease type Ia. Sources cited for classification include the following: PMID 8211187, 22899091, 12373566 and 7573034. Classification of NM_000151.3(G6PC):c.379_380dupTA(Y128Tfs*3) is based on the following criteria: The variant causes a premature termination codon that is expected to be targeted by nonsense-mediated mRNA decay and is reported in individuals with the relevant phenotype. Please note: this variant was assessed in the context of healthy population screening. -
not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	The G6PC c.379_380dupTA (p.Tyr128ThrfsTer3) variant, also referred to as c.376_377insTA, causes a frameshift and is predicted to truncate the protein. The p.Tyr128ThrfsTer3 variant was first identified by Lei et al. (1993) in a homozygous state in an individual whose liver biopsy contained no detectable G6Pase activity. Since then, the variant has been identified in several affected Hispanic individuals in both the homozygous and compound heterozygous state, and is a known common variant in individuals with glycogen storage disease (GSD) type Ia, accounting for approximately 50% of disease alleles in Hispanic populations (Lei et al. 1995; Rake et al. 2000; Matern et al. 2002; Koeberl et al. 2009; Wang et al. 2013). The variant was also shown to segregate with disease (Lei et al. 1995). Control data are not reported for this variant in these studies, but the variant is reported at a frequency of 0.00115 in the Latino population of the Exome Aggregation Consortium. Transient expression analysis of the p.Tyr128ThrfsTer3 variant showed the variant abolished G6Pase activity (Rake et al. 2000). Based on the collective evidence, the p.Tyr128ThrfsTer3 variant is classified as pathogenic for glycogen storage disease type I. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Pathogenic, no assertion criteria provided	literature only	National Center for Biotechnology Information, National Institutes of Health	Aug 25, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Jun 30, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Feb 14, 2021	Variant summary: G6PC c.379_380dupTA (p.Tyr128ThrfsX3) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 0.00011 in 251208 control chromosomes. c.379_380dupTA has been reported in the literature in multiple individuals affected with Glycogen Storage Disease Type Ia (example, Lei_1993, Wang_2013, Peeks_2017). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function (Lei_1993). The most pronounced variant effect results in no detectable G6Pase activity in liver biopsy specimens from an affected patient. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 29, 2024	This sequence change creates a premature translational stop signal (p.Tyr128Thrfs*3) in the G6PC gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in G6PC are known to be pathogenic (PMID: 8182131). This variant is present in population databases (rs756356652, gnomAD 0.07%). This premature translational stop signal has been observed in individuals with glycogen storage disease type Ia (PMID: 8211187, 22899091, 28397058). ClinVar contains an entry for this variant (Variation ID: 11997). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 13, 2024	- -

not provided Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Dec 12, 2023	Published functional studies demonstrate a damaging effect, abolishing G6pase catalytic activity completely (PMID: 7814621); Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 8211187, 31589614, 34258141, 28397058, 7814621) -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Feb 20, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Jun 12, 2023	PP4, PM2, PM3, PS4_moderate, PVS1 -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics	Oct 24, 2016	- -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs80356488; hg19: chr17-41059575;