chr17-42900890-T-G

Position:

• chr17-42900890-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP3_Moderate PP5

The NM_000151.4(G6PC1):​c.14T>G​(p.Met5Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,778 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M5I) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: G6PC1 NM_000151.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4 U:1
• Conservation: PhyloP100: 7.65

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 Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a topological_domain Lumenal (size 27) in uniprot entity G6PC1_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_000151.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-42900891-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2757735.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.931
• PP5: Variant 17-42900890-T-G is Pathogenic according to our data. Variant chr17-42900890-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 555353.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Pathogenic=3, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
G6PC1	NM_000151.4	c.14T>G	p.Met5Arg	missense_variant	1/5	ENST00000253801.7
G6PC1	NM_001270397.2	c.14T>G	p.Met5Arg	missense_variant	1/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
G6PC1	ENST00000253801.7	c.14T>G	p.Met5Arg	missense_variant	1/5	1	NM_000151.4	P1
G6PC1	ENST00000592383.5	c.14T>G	p.Met5Arg	missense_variant	1/5	2
G6PC1	ENST00000585489.1	c.14T>G	p.Met5Arg	missense_variant	1/4	5
G6PC1	ENST00000588481.1	n.79T>G		non_coding_transcript_exon_variant	1/2	2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152154 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

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

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251420 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135888

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461624 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727144

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152154 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74318

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Glycogen storage disease due to glucose-6-phosphatase deficiency type IA Pathogenic:4 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Sep 09, 2021	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 16, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Dec 01, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 12, 2024	This sequence change replaces methionine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 5 of the G6PC protein (p.Met5Arg). This variant is present in population databases (no rsID available, gnomAD 0.002%). This missense change has been observed in individual(s) with glycogen storage disease type 1a (PMID: 12713862). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 555353). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on G6PC protein function. Experimental studies have shown that this missense change affects G6PC function (PMID: 11739393). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.50
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.49
CADD	Uncertain	25
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.89	.;D;.
Eigen	Pathogenic	0.80
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.78	T;T;T
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.93	D;D;D
MetaSVM	Uncertain	0.47	D
MutationAssessor	Uncertain	2.6	M;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-4.7	.;D;.
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	.;D;.
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.96
MutPred		0.72		Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);
MVP		0.92
MPC		0.99
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.96
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1250172816; hg19: chr17-41052907;