chr17-80104783-G-A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PM2PP2BP4_Strong

The NM_000152.5(GAA):c.197G>A(p.Arg66Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000863 in 1,611,530 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R66W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000088 ( 0 hom. )

Consequence

GAA
NM_000152.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:2

Conservation

PhyloP100: -1.65

Publications

9 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: Likely_benign. The variant received -1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 201 curated pathogenic missense variants (we use a threshold of 10). The gene has 50 curated benign missense variants. Gene score misZ: -0.63308 (below the threshold of 3.09). Trascript score misZ: -0.32889 (below the threshold of 3.09). GenCC associations: The gene is linked to glycogen storage disease due to acid maltase deficiency, infantile onset, glycogen storage disease II, glycogen storage disease due to acid maltase deficiency, late-onset.

BP4

Computational evidence support a benign effect (MetaRNN=0.055184364).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAA	NM_000152.5 link	c.197G>A	p.Arg66Gln	missense_variant	Exon 2 of 20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8 link	c.197G>A	p.Arg66Gln	missense_variant	Exon 2 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152178

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000491

AC:

AN:

244618

AF XY:

0.0000300

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000117

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000221

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000182

Gnomad OTH exome

AF:

0.000336

GnomAD4 exome

AF:

0.0000884

AC:

129

AN:

1459236

Hom.:

Cov.:

AF XY:

0.0000771

AC XY:

AN XY:

725896

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33426

American (AMR)

AF:

0.000157

AC:

AN:

44598

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26096

East Asian (EAS)

AF:

0.000152

AC:

AN:

39562

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86018

European-Finnish (FIN)

AF:

0.00

AC:

AN:

51984

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.0000927

AC:

103

AN:

1111482

Other (OTH)

AF:

0.000182

AC:

AN:

60308

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:

0.0000657

AC:

AN:

152294

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74476

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41556

American (AMR)

AF:

0.000196

AC:

AN:

15308

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000882

AC:

AN:

68006

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.505

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:

0.0000332

Hom.:

Bravo

AF:

0.0000756

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Glycogen storage disease, type II

Uncertain:6

Jan 11, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The GAA c.197G>A; p.Arg66Gln variant (rs200202628), to our knowledge, is not reported in the medical literature but is reported in ClinVar (Variation ID: 325775). This variant is observed in the general population with an overall allele frequency of 0.005% (13/275966 alleles) in the Genome Aggregation Database (v2.1.1). Computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.331). Due to limited information, the clinical significance of this variant is uncertain at this time.

Jul 22, 2021

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jul 27, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 66 of the GAA protein (p.Arg66Gln). This variant is present in population databases (rs200202628, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with GAA-related conditions. ClinVar contains an entry for this variant (Variation ID: 325775). 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. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Jan 24, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

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 p.Arg66Gln variant in GAA has not been previously reported in the literature in individuals with Glycogen Storage Disease II but has been reported as a VUS by Invitae and Illumina and a likely benign variant by GeneDx in ClinVar (Variation ID: 325775). This variant has been identified in 0.020% (4/19680) of East Asian chromosomes, 0.014% (5/35104) of Latino chromosomes, and 0.002% (2/125336) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs200202628). 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 suggest that this variant may not impact the protein, though this information is not predictive enough to rule out pathogenicity. The Arginine (Arg) at position 66 is not highly conserved in mammals and evolutionary distant species, and 33 species (including Gibbon, Baboon, Rhesus, Prairie Vole, and Chinchilla) carry an Glutamine (Gln), raising the possibility that this change at this position may be tolerated. In summary, the clinical significance of the p.Arg66Gln variant is uncertain. ACMG/AMP Criteria applied: PM2, BP4 (Richards 2015).

not provided

Uncertain:2

Sep 19, 2024

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

May 02, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 22253258)

Cardiomyopathy

Benign:1

Jan 24, 2019

Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Cardiovascular phenotype

Benign:1

Sep 02, 2025

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.068

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.36

CADD

Benign

0.0020

(source)

DANN

Benign

0.56

DEOGEN2

Benign

0.0035

T;.;T;T

Eigen

Benign

-2.1

Eigen_PC

Benign

-2.2

FATHMM_MKL

Benign

0.023

LIST_S2

Benign

0.40

T;T;.;T

M_CAP

Uncertain

0.13

MetaRNN

Benign

0.055

T;T;T;T

MetaSVM

Benign

-0.61

MutationAssessor

Benign

0.0

.;.;N;N

PhyloP100

-1.7

PrimateAI

Benign

0.27

PROVEAN

Benign

0.0

.;.;N;N

REVEL

Benign

0.0

Sift

Pathogenic

0.0

.;.;T;T

Sift4G

Benign

0.65

T;T;T;T

Vest4

0.0

ClinPred

0.020

GERP RS

-8.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Varity_R

0.016

gMVP

0.23

Mutation Taster

=96/4

polymorphism

(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