rs1555559991

Positions:

• chr17-42909372-C-A

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.516C>A​(p.Tyr172Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: G6PC1 NM_000151.4 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.89

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 does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 28 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-42909372-C-A is Pathogenic according to our data. Variant chr17-42909372-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 558339.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.516C>A	p.Tyr172Ter	stop_gained	4/5	ENST00000253801.7	NP_000142.2
G6PC1	NM_001270397.2	c.439C>A	p.Pro147Thr	missense_variant	4/5		NP_001257326.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
G6PC1	ENST00000253801.7	c.516C>A	p.Tyr172Ter	stop_gained	4/5	1	NM_000151.4	ENSP00000253801	P1
G6PC1	ENST00000592383.5	c.439C>A	p.Pro147Thr	missense_variant	4/5	2		ENSP00000465958
G6PC1	ENST00000585489.1	c.447-1543C>A		intron_variant		5		ENSP00000466202

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Glycogen storage disease due to glucose-6-phosphatase deficiency type IA Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	May 31, 2019	This variant has been observed in an individual affected with glycogen storage disease (PMID: 10070617). ClinVar contains an entry for this variant (Variation ID: 558339). This sequence change creates a premature translational stop signal (p.Tyr172*) in the G6PC gene. It is expected to result in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). Loss-of-function variants in G6PC are known to be pathogenic (PMID: 8182131). For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	May 14, 2018	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.12
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.36	T
MetaRNN	Uncertain	0.74	D
MutationTaster	Benign	1.0	D;D;N
Sift4G	Benign	0.48	T
Vest4		0.46
MVP		0.93
GERP RS		4.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		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: rs1555559991; hg19: chr17-41061389;