rs780226142

Variant names:

• chr17-42911321-C-A
• rs780226142
• NM_000151.4:c.969C>A

Your query was ambiguous. Multiple possible variants found:

• chr17-42911321-C-A
• chr17-42911321-C-T

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_000151.4(G6PC1):​c.969C>A​(p.Tyr323*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000052 in 1,461,894 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 (★★). Synonymous variant affecting the same amino acid position (i.e. Y323Y) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000052 (0 hom.)
• Consequence: G6PC1 NM_000151.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: -0.189
• Publications: 4 publications found

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]

G6PC1 Gene-Disease associations (from GenCC):

• glycogen storage disease due to glucose-6-phosphatase deficiency type IA

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia, Myriad Women’s Health

ACMG classification

Our verdict: Pathogenic. The variant received 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 10 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-42911321-C-A is Pathogenic according to our data. Variant chr17-42911321-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 188777.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000151.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	G6PC1	NM_000151.4	MANE Select	c.969C>A	p.Tyr323*	stop_gained	Exon 5 of 5	NP_000142.2
	G6PC1	NM_001270397.2		c.*361C>A		3_prime_UTR	Exon 5 of 5	NP_001257326.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	G6PC1	ENST00000253801.7	TSL:1 MANE Select	c.969C>A	p.Tyr323*	stop_gained	Exon 5 of 5	ENSP00000253801.1
	G6PC1	ENST00000592383.5	TSL:2	c.*361C>A		3_prime_UTR	Exon 5 of 5	ENSP00000465958.1
	G6PC1	ENST00000585489.1	TSL:5	c.*361C>A		3_prime_UTR	Exon 4 of 4	ENSP00000466202.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000520 AC: 76 AN: 1461894 Hom.: 0 Cov.: 32 AF XY: 0.0000536 AC XY: 39 AN XY: 727248

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000674 AC: 75 AN: 1112012

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000413 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Glycogen storage disease due to glucose-6-phosphatase deficiency type IA Pathogenic:5

Oct 25, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: G6PC c.969C>A (p.Tyr323X) 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 associated with Glycogen Storage Disease in HGMD. The variant was absent in 251410 control chromosomes. c.969C>A has been reported in the literature as a compound heterozygous genotype in individuals affected with Glycogen Storage Disease Type Ia (Calderaro_2013 and Sperb-Ludwig_2019). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. Studies using G6PC-EGFP construct shows undetectable level of protein expression and significantly altered N-linked glycosylatin (Plona_2019) . Two 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.

Jan 05, 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.Tyr323*) in the G6PC gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 35 amino acid(s) of the G6PC protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with glycogen storage disease (PMID: 23046672). ClinVar contains an entry for this variant (Variation ID: 188777). This variant disrupts a region of the G6PC protein in which other variant(s) (p.Gln347*) have been determined to be pathogenic (PMID: 7573034, 8182131, 8733042, 10070617, 11949931, 28397058). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.

May 08, 2014

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.

Apr 20, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Pathogenic:3

Jun 29, 2016

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Mar 27, 2023

Mayo Clinic Laboratories, Mayo Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2, PM3_supporting, PS3, PVS1_strong

Sep 20, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in a patient in the published literature with glycogen storage disease type 1 (PMID: 23046672); Not observed at significant frequency in large population cohorts (gnomAD); Nonsense variant predicted to result in protein truncation, as the last 35 amino acids are lost, and other loss-of-function variants have been reported downstream in HGMD; Published functional studies demonstrate a damaging effect on protein expression (PMID: 34258141); This variant is associated with the following publications: (PMID: 10070617, 11949931, 31508908, 8182131, 7573034, 8733042, 28397058, 23046672, 34258141)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.080
CADD	Benign	23
DANN	Uncertain	0.98
Eigen	Benign	-0.40
Eigen_PC	Benign	-0.79
FATHMM_MKL	Benign	0.26	N
PhyloP100		-0.19
Vest4		0.86
GERP RS		-5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=3/197	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs780226142; hg19: chr17-41063338;