chr17-80107660-C-T
Variant summary
Our verdict is Pathogenic. Variant got 13 ACMG points: 14P and 1B. PM1PM2PM5PP5_Very_StrongBP4
The NM_000152.5(GAA):c.796C>T(p.Pro266Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,460,774 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. 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. P266T) has been classified as Uncertain significance.
Frequency
Consequence
NM_000152.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 13 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
GAA | NM_000152.5 | c.796C>T | p.Pro266Ser | missense_variant | 4/20 | ENST00000302262.8 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
GAA | ENST00000302262.8 | c.796C>T | p.Pro266Ser | missense_variant | 4/20 | 1 | NM_000152.5 | P1 |
Frequencies
GnomAD3 genomes ? Cov.: 34
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1460774Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3AN XY: 726716
GnomAD4 genome ? Cov.: 34
ClinVar
Submissions by phenotype
Glycogen storage disease, type II Pathogenic:5
Pathogenic, criteria provided, single submitter | clinical testing | Baylor Genetics | Jul 26, 2023 | - - |
Likely pathogenic, criteria provided, single submitter | clinical testing | Counsyl | Jan 22, 2018 | - - |
Pathogenic, criteria provided, single submitter | clinical testing | Invitae | Jan 18, 2024 | This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 266 of the GAA protein (p.Pro266Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with glycogen storage disease type II (PMID: 17092519, 28592009, 29124014). ClinVar contains an entry for this variant (Variation ID: 556117). 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) performed at Invitae indicates that this missense variant is not expected to disrupt GAA protein function with a negative predictive value of 95%. Experimental studies have shown that this missense change affects GAA function (PMID: 19862843, 28592009). For these reasons, this variant has been classified as Pathogenic. - |
Pathogenic, criteria provided, single submitter | clinical testing | Women's Health and Genetics/Laboratory Corporation of America, LabCorp | Apr 12, 2022 | Variant summary: GAA c.796C>T (p.Pro266Ser) results in a non-conservative amino acid change located in the Glycoside hydrolase family 31, N-terminal domain of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 250862 control chromosomes. c.796C>T has been reported in the literature in individuals affected with Glycogen Storage Disease, Type 2 (Pompe Disease). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. - |
Likely pathogenic, reviewed by expert panel | curation | ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel | Jun 30, 2022 | The NM_000152.5:c.796C>T variant in GAA is a missense variant predicted to cause substitution of proline by serine at amino acid 266 (p.Pro266Ser). At least seven patients with this variant and features consistent with Pompe disease have been reported. This includes 2 patients with documented laboratory values showing deficient GAA activity (<10% normal or below reference range in leukocytes) (PMID: 17092519, 29124014) (PP4_Moderate). These patients are all compound heterozygous for the variant and another variant in GAA classified as pathogenic or likely pathogenic by the ClinGen LSD VCEP, phase unknown, including c.1309C>T (p.Arg437Cys) (PMID: 25526786), c.1316T>A (p.Met439Lys) (PMID: 17092519, 31193175,), c.1935C>A (p.Asp645Glu) (PMID: 28394184) (ClinVar# SCV002032138.1), c.546G>T (PMID: 29124014) (ClinVar# SCV002032139.1), and c.1602_1605delinsAGG (p.Asn535GlyfsTer43) (PMID: 28394184) (PM3_Strong). This variant is absent in gnomAD v2.1.1 (PM2_Supporting). This variant resulted in 14-18% wild type GAA activity, in two different studies, when expressed in COS cells. (PMID: 18425781, 19862843). Western blot revealed presence of the active 76kDa GAA band, but at a much lower level than wild type (PMID: 19862843). Additional variants at this amino acid positions have been reported (c.797C>T (p.Pro266Leu); c.796C>A (p.Pro266Thr) (PMID: 29451150); these variants have not been classified as pathogenic or likely pathogenic by the ClinGen LSD VCEP. The score from the in silico metapredictor REVEL is 0.476 (BP4), which is a single piece of conflicting evidence in comparison with the evidence for pathogenicity. There is a ClinVar entry for this variant (Variation ID:556117, 2 star review status) with two submitters classifying the variant as pathogenic and one as likely pathogenic. In summary, based on the overall evidence, this variant meets the criteria to be classified as likely pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen LSD VCEP (Specifications Version 2): PM3_Strong, PP4_Moderate, PS3_Supporting, PM2_Supporting, BP4. - |
not provided Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | GeneDx | Dec 17, 2019 | Reported in ClinVar as a likely pathogenic variant (ClinVar Variant ID# 556117; Landrum et al., 2016); Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Published functional studies demonstrate a damaging effect as COS-7 cells with this variant had 14% residual enzyme activity compared to wild type (Flanagan et al., 2009); This variant is associated with the following publications: (PMID: 30275481, 25526786, 20080426, 18211760, 28592009, 24169249, 29124014, 17092519, 19862843) - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at