rs770276275

Variant names:

• chr17-80110028-CGAGA-C
• rs770276275
• NM_000152.5:c.1411_1414delGAGA

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PP4 PM2 PVS1

This summary comes from the ClinGen Evidence Repository: This variant, c.1411_1414del (p.Glu471ProfsTer5), is a frameshift variant that is predicted to result in a premature termination codon, nonsense mediated decay, and lack of gene product. Therefore, PVS1 can be applied. The highest population minor allele frequency in gnomAD v2.1.1 is 0.0002513 in the East Asian population, meeting PM2. This variant has been reported multiple times in Asian patients with Pompe disease presenting clinically and identified by newborn screening. At least eight patients with Pompe disease and meeting the ClinGen LSD VCEP’s specifications for PP4 have been reported as compound heterozygous with either c.214C>A (p.Leu141Met), c.872T>C, (p.Leu291Pro), c.1933G>C (p.Asp645His), or c.1935C>A (p.Asp645Glu) (PMIDs 8604985, 18458862, 24243590, 31510962). The in trans data for these patients will be used in the assessment of the missense variants and, therefore, was not included here in order to avoid circular logic. Additional patients with this variant have been reported but were not included because no residual GAA activity provided and, therefore, PP4 could not be assessed (PMIDs 10338092, 25466677, 27183828, 27692865, 28394184, 29122469), or pseudodeficiency alleles are present (PMID 19948615, 21232767, 23632029, 27183828). Of note, the variant has been reported to be in cis with two missense changes, c.[752C>T; 761C>T] (p.[Ser251Leu; Ser254Leu]) (PMIDs 20080426, 25466677, 27183828, 29122469). There is a ClinVar entry for this variant (Variation ID: 188874, 2 star review status) with three submitters classifying the variant as pathogenic, and one as likely pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen LSD VCEP: PVS1, PM2, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA274067/MONDO:0009290/010

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 34)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: GAA NM_000152.5 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:10
• Conservation: PhyloP100: 3.06
• Publications: 7 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: 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	c.1411_1414delGAGA	p.Glu471ProfsTer5	frameshift_variant	Exon 9 of 20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8	c.1411_1414delGAGA	p.Glu471ProfsTer5	frameshift_variant	Exon 9 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152186 Hom.: 0 Cov.: 34

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

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: 0.0000160 AC: 4 AN: 249358 AF XY: 0.00000739

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000218

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1460888 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 726768

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

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44710

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.000126 AC: 5 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111870

Other (OTH) AF: 0.00 AC: 0 AN: 60376

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000494837), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152186 Hom.: 0 Cov.: 34 AF XY: 0.0000134 AC XY: 1 AN XY: 74350

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

African (AFR) AF: 0.00 AC: 0 AN: 41440

American (AMR) AF: 0.00 AC: 0 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.000192 AC: 1 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68034

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: reviewed by expert panel

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:8

Dec 03, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Glu471Profs*5) in the GAA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GAA are known to be pathogenic (PMID: 18425781, 22252923). This variant is present in population databases (rs770276275, gnomAD 0.03%). This premature translational stop signal has been observed in individuals with infantile-onset Pompe disease (PMID: 8604985, 18458862, 28394184, 29046207). ClinVar contains an entry for this variant (Variation ID: 188874). For these reasons, this variant has been classified as Pathogenic. -

Mar 06, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 09, 2014

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

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. -

Oct 24, 2019

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GAA c.1411_1414delGAGA (p.Glu471ProfsX5) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 1.6e-05 in 249358 control chromosomes (gnomAD). c.1411_1414delGAGA has been reported in the literature in multiple individuals affected with Glycogen Storage Disease, Type 2 (Pompe Disease). The variant has predominantly associated with infantile onset of the disease (e.g. Chien_2006, Labrousse_2010, Shieh_1996, Wan_2008). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as pathogenic. -

Jan 22, 2020

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Glu471ProfsTer5 variant in GAA has been reported in 13 individuals from China or Taiwan with Glycogen Storage Disease II (PMID: 28394184, 18458862, 19948615, 10338092, 8604985), and has also been reported likely pathogenic by Counsyl in ClinVar (Variation ID: 188874). This variant has been identified in 0.025% (5/19900) of East Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs770276275). 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 is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at position 471 and leads to a premature termination codon 5 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Loss of function of the GAA gene is an established disease mechanism in autosomal recessive Glycogen Storage Disease II. The presence of this variant in combination with reported pathogenic and likely pathogenic variants and in individuals with Glycogen Storage Disease II increases the likelihood that the p.Glu471ProfsTer5 variant is pathogenic (PMID: 18458862, 19948615, 28394184; Variation ID: 189006, 4029). The phenotype of individuals heterozygous for this variant is highly specific for Glycogen Storage Disease II with abnormally low GAA activity detected by assays with patient fibroblasts and/or lymphocytes (PMID: 18458862, 19948615, 28394184). In summary, this variant meets criteria to be classified as pathogenic for Glycogen Storage Disease II in an autosomal recessive manner based on the predicted impact of the variant and multiple occurrences with pathogenic GAA variants in individuals with Glycogen Storage Disease II. ACMG/AMP Criteria applied: PVS1, PM3, PM2, PP4 (Richards 2015). -

Oct 08, 2020

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

This variant, c.1411_1414del (p.Glu471ProfsTer5), is a frameshift variant that is predicted to result in a premature termination codon, nonsense mediated decay, and lack of gene product. Therefore, PVS1 can be applied. The highest population minor allele frequency in gnomAD v2.1.1 is 0.0002513 in the East Asian population, meeting PM2. This variant has been reported multiple times in Asian patients with Pompe disease presenting clinically and identified by newborn screening. At least eight patients with Pompe disease and meeting the ClinGen LSD VCEP's specifications for PP4 have been reported as compound heterozygous with either c.214C>A (p.Leu141Met), c.872T>C, (p.Leu291Pro), c.1933G>C (p.Asp645His), or c.1935C>A (p.Asp645Glu) (PMIDs 8604985, 18458862, 24243590, 31510962). The in trans data for these patients will be used in the assessment of the missense variants and, therefore, was not included here in order to avoid circular logic. Additional patients with this variant have been reported but were not included because no residual GAA activity provided and, therefore, PP4 could not be assessed (PMIDs 10338092, 25466677, 27183828, 27692865, 28394184, 29122469), or pseudodeficiency alleles are present (PMID 19948615, 21232767, 23632029, 27183828). Of note, the variant has been reported to be in cis with two missense changes, c.[752C>T; 761C>T] (p.[Ser251Leu; Ser254Leu]) (PMIDs 20080426, 25466677, 27183828, 29122469). There is a ClinVar entry for this variant (Variation ID: 188874, 2 star review status) with three submitters classifying the variant as pathogenic, and one as likely pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen LSD VCEP: PVS1, PM2, PP4. -

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Mar 18, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

GAA-related disorder Pathogenic:1

Jun 19, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The GAA c.1411_1414delGAGA variant is predicted to result in a frameshift and premature protein termination (p.Glu471Profs*5). This variant has been reported as compound heterozygous variant in individuals with glycogen storage disease type 2 (GSD II), also known as Pompe disease (Ko et al. 1999. PubMed ID: 10338092; Mori et al. 2017. PubMed ID: 29122469; Chien et al. 2014. PubMed ID: 25466677; Labrousse et al. 2009. PubMed ID: 20080426; Chen et al. 2017. PubMed ID: 28394184). Biochemical studies revealed significantly reduced GAA enzyme activity in individuals with the c.1411_1414del variant (Wan et al. 2008. PubMed ID: 18458862; Labrousse et al. 2009. PubMed ID: 20080426). This variant is reported in 0.025% of alleles in individuals of East Asian descent in gnomAD. Of note, this variant has been reported to be in cis with the c.[752C>T; 761C>T] (p.[Ser251Leu; Ser254Leu]) haplotype (Labrousse et al. 2009. PubMed ID: 20080426; Chien et al. 2014. PubMed ID: 25466677; Mori et al. 2017. PubMed ID: 29122469). The c.1411_1414delGAGA variant has been classified as likely pathogenic by the ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel (LSD VCEP), as well as pathogenic or likely pathogenic by other outside laboratories (https://www.ncbi.nlm.nih.gov/clinvar/variation/188874/). We interpret this variant as pathogenic. -

not provided Pathogenic:1

Oct 29, 2019

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		3.1
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs770276275; hg19: chr17-78083827;