rs535644999

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2_SupportingPM3PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.1375G>A variant in GAA is a missense variant predicted to cause substitution of Asp by Asn at amino acid 459 (p.Asp459Asn). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00041 (14/34538 alleles) in the Admixed American population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.001), meeting this criterion (PM2_Supporting). At least 4 patients have been identified with this variant. Two had documented GAA deficiency, one with <30% of normal mean control level of GAA activity in skin fibroblasts (PMID:21757382; 18458862) and one within affected range in dried blood spot (Clinical diagnostic laboratory). (PP4_Moderate). Of these patients, one was compound heterozygous for the variant and another variant in GAA that has been classified as pathogenic by the ClinGen Lysosomal Diseases Variant Curation Expert Panel, and confirmed to be in trans, c.2173C>T (p.Arg725Trp) (ClinVar Variation ID: 4024, SCV004227911.1). 1 point (PM3). Additional patients had evidence of pseudodeficiency variants with (PMID:21484825, 28302345). The computational predictor REVEL gives a score of 0.531 which is neither above nor below the thresholds predicting a damaging (>0.7) or benign (<0.5) impact on GAA function. There is a ClinVar entry for this variant (Variation ID: 188480). In summary, this variant meets the criteria to be classified as Uncertain significance for Pompe disease based on the GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert panel (Specifications Version 2.0): PM2_supporting, PP4_Moderate, PM3.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on March 5, 2024). LINK:https://erepo.genome.network/evrepo/ui/classification/CA198786/MONDO:0009290/010

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 34)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

GAA
NM_000152.5 missense

Scores

Clinical Significance

Uncertain significance reviewed by expert panel P:4U:9

Conservation

PhyloP100: 6.13

Publications

11 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: Uncertain_significance. The variant received 5 ACMG points.

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.1375G>A	p.Asp459Asn	missense_variant	Exon 9 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.1375G>A	p.Asp459Asn	missense_variant	Exon 9 of 20	1	NM_000152.5	ENSP00000305692.3		P10253

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152260

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000719

AC:

AN:

250268

AF XY:

0.0000590

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000405

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000266

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000287

AC:

AN:

1460938

Hom.:

Cov.:

AF XY:

0.0000303

AC XY:

AN XY:

726796

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.000358

AC:

AN:

44710

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39694

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86240

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52666

Middle Eastern (MID)

AF:

0.000347

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000198

AC:

AN:

1111874

Other (OTH)

AF:

0.00

AC:

AN:

60374

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.470

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152378

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74520

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41594

American (AMR)

AF:

0.000131

AC:

AN:

15310

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.000193

AC:

AN:

5182

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10630

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68038

Other (OTH)

AF:

0.00

AC:

AN:

2116

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000042), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.358

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.000109

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000330

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:4Uncertain:9

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Glycogen storage disease, type II

Pathogenic:4Uncertain:5

Sep 16, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Mar 01, 2024

Lildballe Lab, Aarhus University Hospital

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

PS1(m), PM5(m), PM2(sup), PM1 (sup) -

Jan 31, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 459 of the GAA protein (p.Asp459Asn). This variant is present in population databases (rs535644999, gnomAD 0.04%). This missense change has been observed in individual(s) with Pompe disease (PMID: 18458862, 21484825, 21757382). ClinVar contains an entry for this variant (Variation ID: 188480). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt GAA protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Mar 05, 2024

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance:Uncertain significance

Review Status:reviewed by expert panel

Collection Method:curation

The NM_000152.5:c.1375G>A variant in GAA is a missense variant predicted to cause substitution of Asp by Asn at amino acid 459 (p.Asp459Asn). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00041 (14/34538 alleles) in the Admixed American population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.001), meeting this criterion (PM2_Supporting). At least 4 patients have been identified with this variant. Two had documented GAA deficiency, one with <30% of normal mean control level of GAA activity in skin fibroblasts (PMID: 21757382; 18458862) and one within affected range in dried blood spot (Clinical diagnostic laboratory). (PP4_Moderate). Of these patients, one was compound heterozygous for the variant and another variant in GAA that has been classified as pathogenic by the ClinGen Lysosomal Diseases Variant Curation Expert Panel, and confirmed to be in trans, c.2173C>T (p.Arg725Trp) (ClinVar Variation ID: 4024, SCV004227911.1). 1 point (PM3). Additional patients had evidence of pseudodeficiency variants with (PMID: 21484825, 28302345). The computational predictor REVEL gives a score of 0.531 which is neither above nor below the thresholds predicting a damaging (>0.7) or benign (<0.5) impact on GAA function. There is a ClinVar entry for this variant (Variation ID: 188480). In summary, this variant meets the criteria to be classified as Uncertain significance for Pompe disease based on the GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert panel (Specifications Version 2.0): PM2_supporting, PP4_Moderate, PM3. (Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on March 5, 2024). -

Jan 10, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 05, 2021

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mar 02, 2024

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 22, 2020

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:curation

The heterozygous p.Asp459Asn variant in GAA has been reported in 3 individuals (including 1 individual from China and 1 individual from Taiwan individual) with Glycogen Storage Disease II (PMID: 18458862, 21484825, 21757382), and has been reported as a VUS by EGL, Invitae, GeneDx, and Counsyl in ClinVar (Variation ID: 188480). This variant has been identified in 0.041% (14/34538) of Latino chromosomes, 0.005% (1/18370) of East Asian chromosomes, and 0.003% (3/112916) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs535644999). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. Additional computational prediction tools suggest the variant affects protein structure and stability (PMID: 29061980). However, the Aspartate (Asp) at position 459 is highly conserved in mammals and evolutionary distant species and one additional variant at the same position (p.Asp459His) has been reported as a VUS in ClinVar (Variation ID: 497673), raising the possibility that a change at this position may not be tolerated. The phenotype of individuals heterozygous for this variant is highly specific for Glycogen Storage Disease II based on reduced GAA activity in assays of relevant tissue (PMID: 18458862, 21757382). In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM2, PP4 (Richards 2015). -

Feb 20, 2018

Counsyl

Significance:Uncertain significance

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. -

not provided

Uncertain:3

Oct 08, 2018

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

A variant of uncertain significance has been identified in the GAA gene. The D459N variant in the GAA gene has previously been reported in association with late-onset Pompe disease in individuals who harbored a second missense variant in GAA, although the phase of these variants was not determined in these individuals (Wan et al., 2008; Yang et al., 2011, Bali et al., 2011). This variant is observed in 16/245730 (0.0065%) alleles from individuals of multiple ethnic backgrounds in large population cohorts (Lek et al., 2016). Nevertheless, the D459N variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. In-silico analyses, including protein predictors and evolutionary conservation, support a deleterious effect. Therefore, based on the currently available information, it is unclear whether this variant is pathogenic or rare benign. -

May 10, 2023

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 06, 2016

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Uncertain:1

May 23, 2025

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: GAA c.1375G>A (p.Asp459Asn) results in a conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 7.2e-05 in 250268 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in GAA causing Glycogen Storage Disease, Type 2 (Pompe Disease) (7.2e-05 vs 0.0042), allowing no conclusion about variant significance. c.1375G>A has been observed in individual(s) affected with Glycogen Storage Disease, Type 2 (Pompe Disease) (Wan_2008, Bali_2011, Yang_GAA_2011 and Sawada_2020). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 18458862, 21757382, 21484825, 33073027, 28302345). ClinVar contains an entry for this variant (Variation ID: 188480). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.17

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.25

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.91

D;D

Eigen

Uncertain

0.53

Eigen_PC

Uncertain

0.48

FATHMM_MKL

Uncertain

0.91

LIST_S2

Uncertain

0.97

.;D

M_CAP

Uncertain

0.28

MetaRNN

Pathogenic

0.95

D;D

MetaSVM

Uncertain

0.67

MutationAssessor

Uncertain

2.2

M;M

PhyloP100

6.1

PrimateAI

Uncertain

0.70

PROVEAN

Pathogenic

-4.5

D;D

REVEL

Uncertain

0.53

Sift

Benign

0.040

D;D

Sift4G

Uncertain

0.055

T;T

Polyphen

0.99

D;D

Vest4

0.89

MutPred

0.81

Loss of phosphorylation at Y455 (P = 0.1131);Loss of phosphorylation at Y455 (P = 0.1131);

MVP

1.0

MPC

0.51

ClinPred

0.87

GERP RS

5.4

Varity_R

0.70

gMVP

0.79

Mutation Taster

=10/90

disease causing

(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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rs535644999

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