17-42907543-ATG-GTC

Variant names:

• chr17-42907543-ATG-GTC
• NM_000151.4:c.361_363delATGinsGTC
• G6PC1 p.Met121Val

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PS1 PM1 PM5 PP2 PP3

The NM_000151.4(G6PC1):​c.361_363delATGinsGTC​(p.Met121Val) variant causes a missense change involving the alteration of a 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M121T) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: G6PC1 NM_000151.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.70
• 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: G2P, Myriad Women’s Health, Labcorp Genetics (formerly Invitae)
• glycogen storage disease I

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PS1: Transcript NM_000151.4 (G6PC1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000151.4
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-42907544-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2085726.Status of the report is criteria_provided_single_submitter, 1 stars.
• 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, glycogen storage disease I.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	G6PC1	NM_000151.4	MANE Select	c.361_363delATGinsGTC	p.Met121Val	missense	N/A	NP_000142.2	P35575-1
	G6PC1	NM_001270397.2		c.341-57_341-55delATGinsGTC		intron	N/A	NP_001257326.1	P35575-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	G6PC1	ENST00000253801.7	TSL:1 MANE Select	c.361_363delATGinsGTC	p.Met121Val	missense	N/A	ENSP00000253801.1	P35575-1
	G6PC1	ENST00000887113.1		c.358_360delATGinsGTC	p.Met120Val	missense	N/A	ENSP00000557172.1
	G6PC1	ENST00000585489.1	TSL:5	c.361_363delATGinsGTC	p.Met121Val	missense	N/A	ENSP00000466202.1	K7ELS6

Frequencies

GnomAD3 genomes Cov.: 31

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

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.7

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr17-41059560;