rs786204720

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PP4_ModeratePM3_StrongPM1PP3PS3_ModeratePM2_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.1556T>C variant in GAA is a missense variant predicted to cause substitution of methionine by threonine at amino acid 519 (p.Met519Thr). This variant has been detected in at least 4 individuals with Pompe disease. Of those individuals, 3 were compound heterozygous for the variant and a variant that has been classified as pathogenic by the ClinGen LD VCEP, phase unconfirmed, either c.525del (ClinVar Variation ID: 4033, SCV001443331.1) (PMID:14695532), c.1441T>C (p.Trp481Arg) (ClinVar Variation ID: 189007, SCV004227917.1) (PMID:31086307), or c.[752C>T;761C>T] (p.[Ser251Leu;Ser254Leu] (ClinVar Variation ID 325781/325782) (Clinical laboratory data); One individual was homozygous for the variant (PMID:33741225) (PM3_Strong). At least 1 patient with this variant had documented GAA deficiency with <10% of normal mean control level of GAA activity in dried blood spot (PMID:33741225) and 2 patients were reported to have symptoms consistent with infantile onset Pompe disease (PMID:14695532) (PP4_Moderate). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00003 (1/30616 alleles) in the South Asian population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.001), meeting this criterion (PM2_Supporting). The computational predictor REVEL gives a score of 0.983 which is above the threshold of 0.7, evidence that correlates with impact to GAA function (PP3). Expression of the variant in COS-7 resulted in <2% wild type GAA activity with western blot data showing decreased level of mature protein, indicating that this variant may impact protein function (PMIDs: 19862843, 14695532) (PS3_Moderate). This variant alters amino acid M519, a residue that crystallography studies have shown to be important in the active site of GAA, and therefore has been defined as a critical residue by the ClinGen Lysosomal Diseases VCEP (https://www.biorxiv.org/content/10.1101/212837v1.full.pdf, PMID:29061980) (PM1). There is a ClinVar entry for this variant (Variation ID: 189124). In summary, this variant meets the criteria to be classified as Pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria met, based on the specification of the ClinGen Lysosomal Diseases VCEP (Specifications Version 2.0): PM3_strong, PP4_moderate, PM1, PS3_moderate, PP3, PM2_supporting.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on May 7, 2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA274402/MONDO:0009290/010

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

GAA
NM_000152.5 missense

Scores

Clinical Significance

Pathogenic reviewed by expert panel P:11U:1

Conservation

PhyloP100: 6.02

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PS3

For more information check the summary or visit ClinGen Evidence Repository.

PM1

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.

PP3

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.1556T>C	p.Met519Thr	missense_variant	Exon 11 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.1556T>C	p.Met519Thr	missense_variant	Exon 11 of 20	1	NM_000152.5	ENSP00000305692.3		P10253

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152156

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251282

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135862

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 SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461648

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727110

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152156

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74334

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:11Uncertain:1

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Glycogen storage disease, type II

Pathogenic:9

Oct 15, 2020

Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Met519Thr has been reported by Reuser et. al. 1995 PMID:7603530 -

Jan 29, 2020

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Met519Thr variant in GAA has been reported in 3 individuals (1 Australian, 1 Dutch, and 1 Belgian) with Glycogen Storage Disease II (PMID: 14695532), and has been identified in 0.003% (1/30616) of South Asian chromosomes and 0.001% (1/113600) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs786204720). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported likely pathogenic by Counsyl and a VUS by EGL in ClinVar (Variation ID: 189124). This variant is located in the highly conserved GH31 motif, a region involved in substrate binding (PMID: 19862843, 15501829). In vitro functional studies provide some evidence that the p.Met519Thr variant may impact protein function (PMID: 19862843, 14695532). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. One additional variant at the the same position, p.Met519Val, has been reported in association with disease in the literature, slightly supporting that a change at this position may not be tolerated (PMID: 19862843, 14695532). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic. ACMG/AMP Criteria applied: PS3, PM2, PP3, PM5_Supporting (Richards 2015). -

Jan 14, 2015

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

Jul 22, 2021

Genome-Nilou Lab

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 22, 2022

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). The variant is in trans with NM_000152.5:c.1561G>A variant. In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.98; 3Cnet: 0.92). Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000189124). Different missense changes at the same codon (p.Met519Ile, p.Met519Val) have been reported to be associated with GAA related disorder (ClinVar ID: VCV001067893 / PMID: 31965297, 7866409). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -

May 07, 2024

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000152.5:c.1556T>C variant in GAA is a missense variant predicted to cause substitution of methionine by threonine at amino acid 519 (p.Met519Thr). This variant has been detected in at least 4 individuals with Pompe disease. Of those individuals, 3 were compound heterozygous for the variant and a variant that has been classified as pathogenic by the ClinGen LD VCEP, phase unconfirmed, either c.525del (ClinVar Variation ID: 4033, SCV001443331.1) (PMID: 14695532), c.1441T>C (p.Trp481Arg) (ClinVar Variation ID: 189007, SCV004227917.1) (PMID: 31086307), or c.[752C>T;761C>T] (p.[Ser251Leu;Ser254Leu] (ClinVar Variation ID 325781/325782) (Clinical laboratory data); One individual was homozygous for the variant (PMID: 33741225) (PM3_Strong). At least 1 patient with this variant had documented GAA deficiency with <10% of normal mean control level of GAA activity in dried blood spot (PMID: 33741225) and 2 patients were reported to have symptoms consistent with infantile onset Pompe disease (PMID: 14695532) (PP4_Moderate). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00003 (1/30616 alleles) in the South Asian population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.001), meeting this criterion (PM2_Supporting). The computational predictor REVEL gives a score of 0.983 which is above the threshold of 0.7, evidence that correlates with impact to GAA function (PP3). Expression of the variant in COS-7 resulted in <2% wild type GAA activity with western blot data showing decreased level of mature protein, indicating that this variant may impact protein function (PMIDs: 19862843, 14695532) (PS3_Moderate). This variant alters amino acid M519, a residue that crystallography studies have shown to be important in the active site of GAA, and therefore has been defined as a critical residue by the ClinGen Lysosomal Diseases VCEP (https://www.biorxiv.org/content/10.1101/212837v1.full.pdf, PMID: 29061980) (PM1). There is a ClinVar entry for this variant (Variation ID: 189124). In summary, this variant meets the criteria to be classified as Pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria met, based on the specification of the ClinGen Lysosomal Diseases VCEP (Specifications Version 2.0): PM3_strong, PP4_moderate, PM1, PS3_moderate, PP3, PM2_supporting. (Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on May 7, 2024) -

May 01, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 519 of the GAA protein (p.Met519Thr). This variant is present in population databases (rs786204720, gnomAD 0.003%). This missense change has been observed in individual(s) with Pompe disease (PMID: 31086307, 33741225). ClinVar contains an entry for this variant (Variation ID: 189124). 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 expected to disrupt GAA protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GAA function (PMID: 14695532, 19862843). This variant disrupts the p.Met519 amino acid residue in GAA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 31439017, 31965297; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Dec 29, 2023

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 14, 2023

Neuberg Centre For Genomic Medicine, NCGM

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The missense variant c.1556T>C(p.Met519Thr) in GAA gene has been reported in homozygous state in individuals with Pompe disease (Puri RD, et al., 2021).Experimental studies have shown that this missense change affects GAA function. This variant disrupts the p.Met519 amino acid residue in GAA (Flanagan JJ,et al., 2009). The variant has 0.001% allele frequency in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. This variant has been reported to the ClinVar database as Uncertain significance/ Likely Pathogenic/ Pathogenic.The amino acid Methionine at position 519 is changed to a Threonine changing protein sequence and it might alter its composition and physico-chemical properties. The variant is predicted to be damaging by SIFT. The amino acid change p.Met519Thr in GAA is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:2Uncertain:1

Jun 28, 2023

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 02, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 08, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Published functional studies demonstrate that the variant results in significantly reduced enzyme activity (PMID: 19862843); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 7603530, 14695532, 31086307, 31439017, 31193175, 15501829, 31254424, 33741225, 31965297, 19862843, 19343043, 22253258) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.88

BayesDel_addAF

Pathogenic

0.44

BayesDel_noAF

Pathogenic

0.48

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.98

D;D

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.89

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

.;D

M_CAP

Pathogenic

0.79

MetaRNN

Pathogenic

0.99

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.5

H;H

PrimateAI

Pathogenic

0.80

PROVEAN

Pathogenic

-6.0

D;D

REVEL

Pathogenic

0.98

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

D;D

Vest4

0.98

MutPred

0.94

Gain of glycosylation at M519 (P = 0.025);Gain of glycosylation at M519 (P = 0.025);

MVP

1.0

MPC

0.58

ClinPred

1.0

GERP RS

5.5

Varity_R

0.98

gMVP

0.98

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over