17-80110837-G-A

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PP4PM3_StrongPM2PVS1

This summary comes from the ClinGen Evidence Repository: This variant, c.1548G>A (p.Trp516Ter), is a nonsense variant that is expected to result in nonsense mediated decay and absence of gene product. This is supported by the lack of cross reactive immunological material in cultured fibroblasts from a patient with this variant (PMID 22252923). Therefore, PVS1 can be applied. The highest population minor allele frequency for this variant in gnomAD v2.1.1 is 0.00002 in the European non-Finnish population, meeting the ClinGen LSD VCEP’s threshold for PM2. This variant is reported to be in compound heterozygosity with a unique pathogenic variant (c.-32-13T>G, c.525delT, or c.2481+1022_646+31del) in three patients who also meet the ClinGen LSD VCEP’s specifications for PP4 (PMID 20826098, 22237443, 25243733). In one of these patients, the variants were confirmed to be in trans (PMID 25243733). Therefore, PP4 and PM3_Strong can be applied. Additional cases have been reported but were not included because the residual GAA activity was not provided (and therefore PP4 cannot be assessed) (PMIDs 24715333, 29181627, 30155607), full HGVS nomenclature was not provided (PMID 25626711), a case with the same variant (not confirmed in trans) had already been included (PMID 29122469), or the second variant is a variant of unknown significance (PMID 26873529). There is a ClinVar entry for this variant (Variation ID: 189025, 2 star review status) with 5 submitters classifying the variant as pathogenic and one as likely pathogenic. 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 LSD VCEP: PVS1, PM2, PM3_Strong, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA274281/MONDO:0009290/010

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

GAA
NM_000152.5 stop_gained

Scores

Clinical Significance

Pathogenic reviewed by expert panel P:21

Conservation

PhyloP100: 9.39

Publications

33 publications found

Variant links:

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

GAA links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 15 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.

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 link	c.1548G>A	p.Trp516*	stop_gained	Exon 10 of 20	ENST00000302262.8	NP_000143.2	P10253

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8 link	c.1548G>A	p.Trp516*	stop_gained	Exon 10 of 20	1	NM_000152.5	ENSP00000305692.3		P10253

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251134

AF XY:

0.00

show subpopulations

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:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000506

AC:

AN:

1461796

Hom.:

Cov.:

AF XY:

0.0000481

AC XY:

AN XY:

727198

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53364

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000647

AC:

AN:

1111974

Other (OTH)

AF:

0.0000331

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.482

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74350

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41446

American (AMR)

AF:

0.0000654

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000735

AC:

AN:

68032

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.508

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000531

Hom.:

Bravo

AF:

0.0000340

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000778

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:21

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Glycogen storage disease, type II

Pathogenic:13

Sep 16, 2020

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jan 20, 2025

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.Trp516*) 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 present in population databases (rs140826989, gnomAD 0.002%). This premature translational stop signal has been observed in individual(s) with Pompe disease and low alpha-glucosidase enzyme activity (PMID: 14695532, 22676651, 24715333, 25243733, 29122469, 29181627). ClinVar contains an entry for this variant (Variation ID: 189025). For these reasons, this variant has been classified as Pathogenic. -

Oct 31, 2024

Clinical Genomics Laboratory, Washington University in St. Louis

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The GAA c.1548G>A (p.Trp516*) variant has been reported in at least three individuals affected by glycogen storage disease II (Pompe disease) who were compound heterozygous for this variant and a pathogenic or likely pathogenic variant, with one case confirmed in trans (Bergsma AJ et al., PMID: 25243733; Messinger YH et al., PMID: 22237443; de Vries JM et al., PMID: 20826098). This variant has been reported in the ClinVar database as a pathogenic variant by eighteen submitters, including an expert panel, and as likely pathogenic by one submitter (Variation ID: 189025; Goldstein JL et al., PMID: 37907381). This variant leads to a premature termination codon, which is predicted to lead to nonsense mediated decay. This variant is only observed on 1 out of 13,006 alleles in the general population (gnomAD v.2.1.1), indicating it is not a common variant. Based on available information and the specific GAA-ACMG/AMP guidelines for variant interpretation (Goldstein JL et al., PMID: 37907381; Richards S et al., PMID: 25741868), this variant is classified as pathogenic. -

Jun 11, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 07, 2019

Molecular Therapies Laboratory, Murdoch University

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

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.Trp516Ter variant in GAA has been reported in at least 16 individuals (including at least 10 Caucasian individuals) with Glycogen Storage Disease II (PMID: 22676651, 25155446, 14695532, 17027861, 15048888, 18757064, 20826098, 22237443, 25243733, 24715333, 22252923, 26873529, 23601496), and has also been reported pathogenic by EGL and likely pathogenic by Counsyl in ClinVar (Variation ID: 189025). This variant has been identified in 0.002% (2/128904) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs140826989). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. This nonsense variant leads to a premature termination codon at position 516, 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 3 pathogenic variants, and in individuals with Glycogen Storage Disease II increases the likelihood that the p.Trp516Ter variant is pathogenic (PMID: 20826098, 25243733, 22237443, 22676651; Variation ID: 4031, 4033). The phenotype of six individuals compound heterozygous for this variant is highly specific for Glycogen Storage Disease II based on their low GAA activity within fibroblasts or a dried blood spot (PMID: 20826098, 23601496, 22237443, 25243733, 26873529, 22676651). 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 multiple occurrences with pathogenic GAA variants in individuals with Glycogen Storage Disease II. ACMG/AMP Criteria applied: PVS1, PM3_Strong, PM2, PP4 (Richards 2015). -

Oct 20, 2014

Counsyl

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

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. -

Sep 08, 2021

MGZ Medical Genetics Center

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 09, 2019

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: GAA c.1548G>A (p.Trp516X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 4e-06 in 251134 control chromosomes. c.1548G>A has been reported in the literature in individuals affected with Glycogen Storage Disease, Type 2 (Pompe Disease- eg Hermans_2004, deVries_2010, Messinger_2012, Stepien_2016). These data indicate that the variant is likely to be associated with disease. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar (evaluation after 2014) and cited the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Feb 14, 2020

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance:Pathogenic

Review Status:reviewed by expert panel

Collection Method:curation

This variant, c.1548G>A (p.Trp516Ter), is a nonsense variant that is expected to result in nonsense mediated decay and absence of gene product. This is supported by the lack of cross reactive immunological material in cultured fibroblasts from a patient with this variant (PMID 22252923). Therefore, PVS1 can be applied. The highest population minor allele frequency for this variant in gnomAD v2.1.1 is 0.00002 in the European non-Finnish population, meeting the ClinGen LSD VCEP's threshold for PM2. This variant is reported to be in compound heterozygosity with a unique pathogenic variant (c.-32-13T>G, c.525delT, or c.2481+1022_646+31del) in three patients who also meet the ClinGen LSD VCEP's specifications for PP4 (PMID 20826098, 22237443, 25243733). In one of these patients, the variants were confirmed to be in trans (PMID 25243733). Therefore, PP4 and PM3_Strong can be applied. Additional cases have been reported but were not included because the residual GAA activity was not provided (and therefore PP4 cannot be assessed) (PMIDs 24715333, 29181627, 30155607), full HGVS nomenclature was not provided (PMID 25626711), a case with the same variant (not confirmed in trans) had already been included (PMID 29122469), or the second variant is a variant of unknown significance (PMID 26873529). There is a ClinVar entry for this variant (Variation ID: 189025, 2 star review status) with 5 submitters classifying the variant as pathogenic and one as likely pathogenic. 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 LSD VCEP: PVS1, PM2, PM3_Strong, PP4. -

Jan 05, 2022

DASA

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.1548G>A;p.(Trp516*) variant creates a premature translational stop signal in the GAA gene. It is expected to result in an absent or disrupted protein product -PVS1. This sequence change has been observed in affected individual(s) and ClinVar contains an entry for this variant (Clinvar ID 189025; PMID: 32317649; 30155607; 29181627; 29122469; 26873529) - PS4. The variant is present at low allele frequencies population databases (rs140826989 – gnomAD 0.003942%; ABraOM no frequency - http://abraom.ib.usp.br/) -PM2_supporting. The p.(Trp516*) was detected in trans with a pathogenic variant (PMID: 32317649; 29181627; 29122469; 26873529) - PM3_strong. In summary, the currently available evidence indicates that the variant is pathogenic. -

Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This nonsense variant found in exon 10 of 20 is predicted to result in loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay (NMD). This variant has been previously reported as a compound heterozygous change in patients with Glycogen storage disease II (PMID: 14695532, 29181627, 29122469, 24715333). Loss-of-function variation in GAA is an established mechanism of disease (PMID:18425781, 22252923). This variant has been observed in individuals with low alpha-glucosidase enzyme activity, suggestive of Glycogen storage disease II (PMID: 25243733, 22676651).The c.1548G>A (p.Trp516Ter) variant is present in the heterozygous state in the gnomAD population database at a frequency of 0.00007 (2/282510) and thus is presumed to be rare. Based on the available evidence, the c.1548G>A (p.Trp516Ter) variant is classified as a Pathogenic. -

Feb 09, 2024

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Pathogenic:7

Jun 08, 2018

Eurofins Ntd Llc (ga)

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 08, 2021

AiLife Diagnostics, AiLife Diagnostics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Feb 24, 2023

Revvity Omics, Revvity

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 01, 2019

CeGaT Center for Human Genetics Tuebingen

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jan 31, 2022

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported in multiple unrelated patients with glycogen storage disease type II (GSDII) (Hermans et al. 2004; van et al. 2015; Elder et al. 2013; Bergsma et al. 2015; de Vries JM et al. 2010); Not observed at significant frequency in large population cohorts (gnomAD); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 22252923, 18757064, 34134972, 31965297, 32888769, 31086307, 25525159, 25155446, 29181627, 25541616, 22676651, 24715333, 20826098, 23601496, 15048888, 25243733, 14695532) -

GAA-related disorder

Pathogenic:1

Jun 01, 2024

PreventionGenetics, part of Exact Sciences

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

The GAA c.1548G>A variant is predicted to result in premature protein termination (p.Trp516*). This variant has been reported in multiple unrelated patients with glycogen storage disease type II (GSDII) together with another pathogenic variant in GAA (see example: Hermans et al. 2004. PubMed ID: 14695532; Löscher et al. 2018. PubMed ID: 29181627). This variant is reported in 0.0016% of alleles in individuals of European (Non-Finnish) descent in gnomAD. Nonsense variants in GAA are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.63

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

0.83

Eigen_PC

Pathogenic

0.69

FATHMM_MKL

Pathogenic

0.99

PhyloP100

9.4

Vest4

0.90

GERP RS

4.4

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over