NM_000151.4:c.6_7delGGinsAA

Variant names:

• chr17-42900882-GG-AA
• NM_000151.4:c.6_7delGGinsAA

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1 PP2

The NM_000151.4(G6PC1):​c.6_7delGGinsAA​(p.Glu3Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. E2E) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: G6PC1 NM_000151.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.03
• Publications: 0 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: Uncertain_significance. The variant received 3 ACMG points.

• PM1: In a topological_domain Lumenal (size 27) in uniprot entity G6PC1_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_000151.4
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 59 curated pathogenic missense variants (we use a threshold of 10). The gene has 19 curated benign missense variants. Gene score misZ: 0.2658 (below the threshold of 3.09). Trascript score misZ: 1.1659 (below the threshold of 3.09). GenCC associations: The gene is linked to glycogen storage disease due to glucose-6-phosphatase deficiency type IA.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
G6PC1	NM_000151.4	c.6_7delGGinsAA	p.Glu3Lys	missense_variant		ENST00000253801.7	NP_000142.2
G6PC1	NM_001270397.2	c.6_7delGGinsAA	p.Glu3Lys	missense_variant			NP_001257326.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
G6PC1	ENST00000253801.7	c.6_7delGGinsAA	p.Glu3Lys	missense_variant		1	NM_000151.4	ENSP00000253801.1
G6PC1	ENST00000592383.5	c.6_7delGGinsAA	p.Glu3Lys	missense_variant		2		ENSP00000465958.1
G6PC1	ENST00000585489.1	c.6_7delGGinsAA	p.Glu3Lys	missense_variant		5		ENSP00000466202.1
G6PC1	ENST00000588481.1	n.71_72delGGinsAA		non_coding_transcript_exon_variant	Exon 1 of 2	2

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Jun 26, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant has not been reported in the literature in individuals affected with G6PC-related conditions. Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 3 of the G6PC protein (p.Glu3Lys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		3.0

Splicing

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

Other links and lift over

hg19: chr17-41052899;