chr17-80112907-T-G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP7BP4

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.1920T>G variant in GAA is a synonymous (silent) variant that does not change the encoded amino acid (p.Pro640=) and is not predicted to impact splicing. This variant has not been reported as disease-causing in an individual with Pompe disease. It has been described as a polymorphism in a cohort of patients with infantile or juvenile-onset Pompe disease from Taiwan (PMID:18458862). It was also reported in two patients in a European cohort with limb-girdle muscle weakness without a second variant (PMID:29149851). Thus, there is insufficient data to apply PP4. The highest population minor allele frequency in gnomAD v3.1.2 is [0.001534] (8/5184 alleles) in East Asian population. This is higher than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.001), and lower than the threshold for BS1 (>0.005). Therefore none of the population data codes are met. This variant is a synonymous (silent) variant that is not predicted by SpliceAI to impact splicing. In addition, it occurs at a nucleotide that is not conserved as shown by PhyloP100 (-2.182) and PhastCons (0.000) (BP4, BP7). There is a ClinVar entry for this variant (Variation ID: 255358; 1-star review status) with 10 submitters classifying the variant as uncertain significance (4) or likely benign (6). In summary, this variant meets the criteria to be classified as likely benign for Pompe disease based on the ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert panel (Specifications Version 2.0): BP4, BP7.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on May 7, 2024). LINK:https://erepo.genome.network/evrepo/ui/classification/CA8815546/MONDO:0009290/010

Frequency

Genomes: 𝑓 0.00014 ( 1 hom., cov: 33)

Exomes 𝑓: 0.00010 ( 0 hom. )

Consequence

GAA
NM_000152.5 synonymous

Scores

Clinical Significance

Likely benign reviewed by expert panel U:4B:9

Conservation

PhyloP100: -2.18

Publications

2 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 -2 ACMG points.

BP4

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

BP7

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.1920T>G	p.Pro640Pro	synonymous_variant	Exon 14 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.1920T>G	p.Pro640Pro	synonymous_variant	Exon 14 of 20	1	NM_000152.5	ENSP00000305692.3		P10253

Frequencies

GnomAD3 genomes

AF:

0.000145

AC:

AN:

152164

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:

0.00154

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.000377

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000118

Gnomad OTH

AF:

0.000957

GnomAD2 exomes

AF:

0.000181

AC:

AN:

242468

AF XY:

0.000152

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000994

Gnomad FIN exome

AF:

0.000387

Gnomad NFE exome

AF:

0.000146

Gnomad OTH exome

AF:

0.000168

GnomAD4 exome

AF:

0.000102

AC:

149

AN:

1458230

Hom.:

Cov.:

AF XY:

0.000120

AC XY:

AN XY:

725054

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33456

American (AMR)

AF:

0.00

AC:

AN:

44424

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26006

East Asian (EAS)

AF:

0.000555

AC:

AN:

39652

South Asian (SAS)

AF:

0.0000585

AC:

AN:

85488

European-Finnish (FIN)

AF:

0.000496

AC:

AN:

52392

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5752

European-Non Finnish (NFE)

AF:

0.0000810

AC:

AN:

1110802

Other (OTH)

AF:

0.0000996

AC:

AN:

60258

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.510

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:

0.000144

AC:

AN:

152282

Hom.:

Cov.:

AF XY:

0.000148

AC XY:

AN XY:

74468

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41566

American (AMR)

AF:

0.00

AC:

AN:

15298

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00155

AC:

AN:

5172

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.000377

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000118

AC:

AN:

68008

Other (OTH)

AF:

0.000947

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.510

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:

0.000123

Hom.:

Bravo

AF:

0.0000982

ClinVar

Significance: Likely benign

Submissions summary: Uncertain:4Benign:9

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Glycogen storage disease, type II

Uncertain:3Benign:3

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 c.1920T>G (p.Pro640=) variant in GAA has not been reported in individuals with Glycogen Storage Disease II but has been reported in 2 European individuals with unexplained limb-girdle muscle weakness (PMID: 29149851). This variant has also been reported likely benign (by GeneDx, PreventionGenetics, Mayo Clinic Genetic Testing Laboratories, and Invitae) and as a VUS by EGL in ClinVar (Variation ID: 255358). This variant has been identified in 0.09150% (18/19672) of East Asian chromosomes, 0.04553% (11/24162) of European (Finnish) chromosomes, and 0.01683% (21/124752) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs144090460). 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. However, novel synonymous variants supported by computational evidence without raised suspicion for an impact are likely benign (Richards 2015). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely benign. ACMG/AMP Criteria applied: PM2, BP4, BP7 (Richards 2015). -

Jul 22, 2021

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 28, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

May 07, 2024

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance:Likely benign

Review Status:reviewed by expert panel

Collection Method:curation

The NM_000152.5:c.1920T>G variant in GAA is a synonymous (silent) variant that does not change the encoded amino acid (p.Pro640=) and is not predicted to impact splicing. This variant has not been reported as disease-causing in an individual with Pompe disease. It has been described as a polymorphism in a cohort of patients with infantile or juvenile-onset Pompe disease from Taiwan (PMID:18458862). It was also reported in two patients in a European cohort with limb-girdle muscle weakness without a second variant (PMID: 29149851). Thus, there is insufficient data to apply PP4. The highest population minor allele frequency in gnomAD v3.1.2 is [0.001534] (8/5184 alleles) in East Asian population. This is higher than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.001), and lower than the threshold for BS1 (>0.005). Therefore none of the population data codes are met. This variant is a synonymous (silent) variant that is not predicted by SpliceAI to impact splicing. In addition, it occurs at a nucleotide that is not conserved as shown by PhyloP100 (-2.182) and PhastCons (0.000) (BP4, BP7). There is a ClinVar entry for this variant (Variation ID: 255358; 1-star review status) with 10 submitters classifying the variant as uncertain significance (4) or likely benign (6). In summary, this variant meets the criteria to be classified as likely benign for Pompe disease based on the ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert panel (Specifications Version 2.0): BP4, BP7. (Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on May 7, 2024). -

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 15, 2020

Natera, Inc.

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

not provided

Uncertain:1Benign:4

Nov 11, 2015

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 14, 2021

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 24444888, 18458862) -

May 10, 2017

Mayo Clinic Laboratories, Mayo Clinic

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Oct 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

GAA: BP4, BP7 -

Nov 20, 2023

Revvity Omics, Revvity

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Benign:1

PreventionGenetics, part of Exact Sciences

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Benign:1

Aug 03, 2022

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

BayesDel_noAF

Benign

-0.71

CADD

Benign

8.3

(source)

DANN

Benign

0.63

PhyloP100

-2.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=100/0

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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