17-80107807-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1PM2PP2BP4_Moderate

The NM_000152.5(GAA):c.866C>T(p.Ala289Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,611,348 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 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. A289E) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

GAA
NM_000152.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 0.871

Publications

5 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 3 ACMG points.

PM1

In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_000152.5

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=0.15618423).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAA	NM_000152.5 link	c.866C>T	p.Ala289Val	missense_variant	Exon 5 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.866C>T	p.Ala289Val	missense_variant	Exon 5 of 20	1	NM_000152.5	ENSP00000305692.3		P10253

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152150

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000205

AC:

AN:

244382

AF XY:

0.0000225

show subpopulations

Gnomad AFR exome

AF:

0.0000640

Gnomad AMR exome

AF:

0.0000293

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000182

Gnomad OTH exome

AF:

0.000168

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1459198

Hom.:

Cov.:

AF XY:

0.0000152

AC XY:

AN XY:

725864

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33458

American (AMR)

AF:

0.0000225

AC:

AN:

44498

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26074

East Asian (EAS)

AF:

0.00

AC:

AN:

39648

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86100

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52146

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5620

European-Non Finnish (NFE)

AF:

0.0000126

AC:

AN:

1111430

Other (OTH)

AF:

0.0000498

AC:

AN:

60224

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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:

0.0000197

AC:

AN:

152150

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74332

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41424

American (AMR)

AF:

0.0000654

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68016

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000508

Hom.:

Bravo

AF:

0.0000151

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00000825

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Glycogen storage disease, type II

Uncertain:3

Sep 05, 2021

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Aug 31, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine with valine at codon 289 of the GAA protein (p.Ala289Val). The alanine residue is weakly conserved and there is a small physicochemical difference between alanine and valine. This variant is present in population databases (rs145903608, ExAC 0.01%). 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: 285344). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

Dec 08, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

not provided

Uncertain:2

Jan 11, 2018

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 03, 2019

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Benign:1

Jun 10, 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

0.078

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.39

CADD

Benign

1.9

(source)

DANN

Benign

0.87

DEOGEN2

Uncertain

0.44

T;T

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.052

LIST_S2

Benign

0.80

.;T

M_CAP

Uncertain

0.087

MetaRNN

Benign

0.16

T;T

MetaSVM

Benign

-0.66

MutationAssessor

Benign

0.34

N;N

PhyloP100

0.87

PrimateAI

Benign

0.29

PROVEAN

Benign

-0.81

N;N

REVEL

Benign

0.10

Sift

Benign

0.61

T;T

Sift4G

Benign

0.65

T;T

Polyphen

0.0030

B;B

Vest4

0.054

MVP

0.92

MPC

0.11

ClinPred

0.029

GERP RS

0.39

Varity_R

0.090

gMVP

0.58

Mutation Taster

=97/3

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over