rs200483245

Variant names:

• chr17-80117047-C-T
• rs200483245
• NM_000152.5:c.2269C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PP4 PVS1 PM2

This summary comes from the ClinGen Evidence Repository: This variant, c.2269C>T (p.Gln757Ter), which results in a premature termination codon, is expected to undergo nonsense medicated decay resulting in absence of gene product, meeting PVS1. The variant is absent in gnomAD v2.1.1, meeting PM2. One patient meeting the ClinGen LSD VCEP’s specifications for PP4 and compound heterozygous for this variant and c.925G>A (p.Gly309Arg) in GAA has been reported (PMID 24337590). The phase of the variants was not confirmed. In trans data from this patient was used in the assessment of p.Gly309Arg and was not included here in order to avoid circular logic. Additional cases have been reported but were not included because the residual GAA activity was not provided, and therefore PP4 cannot be assessed (PMIDs 17723315, 29149851). There is a ClinVar entry for this variant (Variation ID: 429727, 2 star review status) with two submitters classifying the variant as pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for GSD Pompe disease. GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen LSD VCEP: PVS1, PM2, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA294856548/MONDO:0009290/010

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GAA NM_000152.5 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:10
• Conservation: PhyloP100: 3.74
• Publications: 4 publications found

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]

GAA Gene-Disease associations (from GenCC):

• glycogen storage disease II

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), PanelApp Australia, ClinGen, G2P
• glycogen storage disease due to acid maltase deficiency, infantile onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• glycogen storage disease due to acid maltase deficiency, late-onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 11 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.
• PP4: 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.2269C>T	p.Gln757*	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.2269C>T	p.Gln757*	stop_gained	Exon 16 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00 AC: 0 AN: 250796 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461274 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726942

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52824

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: reviewed by expert panel

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:7

Jan 03, 2017

Counsyl

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

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. -

Feb 09, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Gln757*) in the GAA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GAA are known to be pathogenic (PMID: 18425781, 22252923). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Pompe disease (PMID: 17723315, 29149851). ClinVar contains an entry for this variant (Variation ID: 429727). For these reasons, this variant has been classified as Pathogenic. -

May 30, 2025

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

May 05, 2020

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

This variant, c.2269C>T (p.Gln757Ter), which results in a premature termination codon, is expected to undergo nonsense medicated decay resulting in absence of gene product, meeting PVS1. The variant is absent in gnomAD v2.1.1, meeting PM2. One patient meeting the ClinGen LSD VCEP's specifications for PP4 and compound heterozygous for this variant and c.925G>A (p.Gly309Arg) in GAA has been reported (PMID 24337590). The phase of the variants was not confirmed. In trans data from this patient was used in the assessment of p.Gly309Arg and was not included here in order to avoid circular logic. Additional cases have been reported but were not included because the residual GAA activity was not provided, and therefore PP4 cannot be assessed (PMIDs 17723315, 29149851). There is a ClinVar entry for this variant (Variation ID: 429727, 2 star review status) with two submitters classifying the variant as pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for GSD Pompe disease. GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen LSD VCEP: PVS1, PM2, PP4. -

Jan 22, 2020

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Gln757Ter variant in GAA has been reported in 1 Serbian, 1 Croatian, and 1 Canadian individuals with Glycogen Storage Disease II (PMID: 29149851, 24337590, 17723315), and has also been reported pathogenic by GeneDx and Counsyl in ClinVar (Variation ID: 429727). This variant was absent from genomes and no high quality genotypes at this site were noted to include this variant in exomes from the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs200483245). This nonsense variant leads to a premature termination codon at position 757, which is predicted to lead to a truncated or absent protein. Loss of function of the GAA gene is an established disease mechanism in autosomal recessive Glycogen Storage Disease II. The presence of this variant in combination with a pathogenic variant in an individual with Glycogen Storage Disease II increases the likelihood that the p.Gln757Ter variant is pathogenic (PMID: 24337590). The phenotype of this individual compound heterozygous for this variant is highly specific for Glycogen Storage Disease II with less than 3% of normal GAA activity detected in their lymphocytes (PMID: 24337590). In summary, this variant meets criteria to be classified as pathogenic for Glycogen Storage Disease II in an autosomal recessive manner based on the predicted impact of the variant and the occurrence with a pathogenic GAA variant in an individual with Glycogen Storage Disease II. ACMG/AMP Criteria applied: PVS1, PM2_supporting, PM3_supporting, PP4 (Richards 2015). -

Aug 02, 2024

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:3

Jan 23, 2020

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 03, 2015

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Q757X nonsense pathogenic variant in the GAA gene has been reported previously in a patient with adult-onsetGSDII, who also harbored the common c.-32-13 T>G variant (McCready et al., 2007). This pathogenic variant ispredicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNAdecay. The Q757X pathogenic variant was not observed in approximately 6,500 individuals of European and AfricanAmerican ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in thesepopulations -

Oct 01, 2020

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	38
DANN	Uncertain	0.99
Eigen	Uncertain	0.33
Eigen_PC	Benign	0.046
FATHMM_MKL	Uncertain	0.82	D
PhyloP100		3.7
Vest4		0.95
GERP RS		1.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=1/199	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs200483245; hg19: chr17-78090846;