17-80117020-G-T

Variant names:

• chr17-80117020-G-T
• rs1057516363
• NM_000152.5:c.2242G>T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1 PM3_Supporting PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.2242G>T (p.Glu748Ter) variant in GAA is a nonsense variant predicted to cause a premature stop codon in biologically-relevant-exon 16/20, leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). One patient with this variant, diagnosed with late onset Pompe disease, has been reported (PMID:31545528). This individual is compound heterozygous for the variant and a pathogenic variant in GAA, c.-32-13T>G, phase unknown (PMID:31545528) (PM3_Supporting). The data are insufficient to apply PP4 based on the specifications of the ClinGen Lysosomal Diseases VCEP. The variant is absent in gnomAD v2.1.1. (PM2_Supporting). There is a ClinVar entry for this variant (Variation ID 370268). In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases VCEP (Specifications Version 2.0): PVS1, PM3_Supporting, PM2_Supporting.(Classification approved by the ClinGen Lysosomal Diseases VCEP, April 11, 2023). LINK:https://erepo.genome.network/evrepo/ui/classification/CA16041903/MONDO:0009290/010

• Frequency: Genomes: not found (cov: 33)
• Consequence: GAA NM_000152.5 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:3
• Conservation: PhyloP100: 0.773

Genes affected

GAA (HGNC:4065): (alpha glucosidase) This gene encodes lysosomal alpha-glucosidase, which is essential for the degradation of glycogen to glucose in lysosomes. The encoded preproprotein is proteolytically processed to generate multiple intermediate forms and the mature form of the enzyme. Defects in this gene are the cause of glycogen storage disease II, also known as Pompe's disease, which is an autosomal recessive disorder with a broad clinical spectrum. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAA	NM_000152.5	c.2242G>T	p.Glu748*	stop_gained	Exon 16 of 20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8	c.2242G>T	p.Glu748*	stop_gained	Exon 16 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: reviewed by expert panel

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:3

Oct 24, 2022

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 29, 2015

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 11, 2023

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000152.5:c.2242G>T (p.Glu748Ter) variant in GAA is a nonsense variant predicted to cause a premature stop codon in biologically-relevant-exon 16/20, leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). One patient with this variant, diagnosed with late onset Pompe disease, has been reported (PMID: 31545528). This individual is compound heterozygous for the variant and a pathogenic variant in GAA, c.-32-13T>G, phase unknown (PMID: 31545528) (PM3_Supporting). The data are insufficient to apply PP4 based on the specifications of the ClinGen Lysosomal Diseases VCEP. The variant is absent in gnomAD v2.1.1. (PM2_Supporting). There is a ClinVar entry for this variant (Variation ID 370268). In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases VCEP (Specifications Version 2.0): PVS1, PM3_Supporting, PM2_Supporting. (Classification approved by the ClinGen Lysosomal Diseases VCEP, April 11, 2023). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Uncertain	0.44
Eigen_PC	Benign	0.18
FATHMM_MKL	Benign	0.13	N
Vest4		0.94
GERP RS		1.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1057516363; hg19: chr17-78090819;