rs80356482
Variant summary
Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong
The NM_000151.4(G6PC1):c.562G>A(p.Gly188Ser) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000454 in 1,608,354 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 14/25 in silico tools predict a damaging outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G188D) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000151.4 missense, splice_region
Scores
Clinical Significance
Conservation
Publications
- glycogen storage disease due to glucose-6-phosphatase deficiency type IAInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia, Myriad Women’s Health
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ACMG classification
Our verdict: Pathogenic. The variant received 19 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| G6PC1 | NM_000151.4 | c.562G>A | p.Gly188Ser | missense_variant, splice_region_variant | Exon 4 of 5 | ENST00000253801.7 | NP_000142.2 | |
| G6PC1 | NM_001270397.2 | c.485G>A | p.Arg162Lys | missense_variant, splice_region_variant | Exon 4 of 5 | NP_001257326.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| G6PC1 | ENST00000253801.7 | c.562G>A | p.Gly188Ser | missense_variant, splice_region_variant | Exon 4 of 5 | 1 | NM_000151.4 | ENSP00000253801.1 | ||
| G6PC1 | ENST00000592383.5 | c.485G>A | p.Arg162Lys | missense_variant, splice_region_variant | Exon 4 of 5 | 2 | ENSP00000465958.1 | |||
| G6PC1 | ENST00000585489.1 | c.447-1497G>A | intron_variant | Intron 3 of 3 | 5 | ENSP00000466202.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152136Hom.: 0 Cov.: 31 show subpopulations
GnomAD2 exomes AF: 0.0000159 AC: 4AN: 251448 AF XY: 0.0000294 show subpopulations
GnomAD4 exome AF: 0.0000488 AC: 71AN: 1456218Hom.: 0 Cov.: 29 AF XY: 0.0000414 AC XY: 30AN XY: 724942 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152136Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 74312 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Glycogen storage disease due to glucose-6-phosphatase deficiency type IA Pathogenic:9
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. -
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Variant summary: G6PC1 c.562G>A (p.Gly188Ser; also described as G641A in the literature) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. Several computational tools predict a significant impact on normal splicing: Three predict the variant weakens a 5' donor site. One predicts the variant abolishes a 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.6e-05 in 251448 control chromosomes (gnomAD). c.562G>A has been reported in the literature in individuals affected with Glycogen Storage Disease Type Ia (examples: Lei_1995, Matern_2002, Jun_2014, internal testing). These data indicate that the variant is likely to be associated with disease. In vitro functional studies show reduced activity for the variant (example: Lei_1995, Shieh_2002). The following publications have been ascertained in the context of this evaluation (PMID: 7573034, 12373566, 11739393, 24565827). ClinVar contains an entry for this variant (Variation ID: 214465). Based on the evidence outlined above, the variant was classified as pathogenic. -
The c.562G>A (p.G188S) missense variant has been reported in individuals with glycogen storage disease type Ia (PMID: 7573034; 12373566; 24565827). -
This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 188 of the G6PC protein (p.Gly188Ser). This variant also falls at the last nucleotide of exon 4, which is part of the consensus splice site for this exon. This variant is present in population databases (rs80356482, gnomAD 0.004%). This missense change has been observed in individuals with glycogen storage disease type 1A (PMID: 7573034, 24565827; Invitae). This variant is also known as c.641G>A or G641A. ClinVar contains an entry for this variant (Variation ID: 214465). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects G6PC function (PMID: 11739393). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts the p.Gly188 amino acid residue in G6PC. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8733042, 10834516, 10960498, 11739393). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
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not provided Pathogenic:2
G6PC1: PM2, PM5, PP4:Moderate, PS3:Moderate, PM3:Supporting, PP3 -
The G188S missense pathogenic variant in the G6PC gene has been reported previously in association with glycogen storage disease type 1a (Lei et al., 1995). Expression studies found that the G188S mutation abolishes G6Pase activity (Lei et al., 1995). Furthermore, G188S is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species, and another missense mutation at the same position (G188R) has also been reported in association with glycogen storage disease type 1a. Therefore, we interpret G188S to be a pathogenic variant. The variant is found in MITONUC-MITOP panel(s). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at