NM_000152.5:c.1128_1129delGGinsC

Variant names:

• chr17-80108541-GG-C
• rs786204646
• NM_000152.5:c.1128_1129delGGinsC

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PVS1 PM2 PM3 PP4

This summary comes from the ClinGen Evidence Repository: This variant, c.1128_1129delGGinsC (p.Trp376Cysfs), 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 variant is absent in gnomAD v2.1.1, meeting PM2. Two individuals have been reported who meet the ClinGen LSD VCEP’s specifications for PP4 and who are compound heterozygous for c.1128_1129delGGinsC (p.Trp376Cysfs) and a unique pathogenic variant in GAA; one individual has infantile-onset Pompe disease and is compound heterozygous for the variant and c.2237G>A (p.Trp746Ter), phase unknown (PMID 22237443), the second individual has late onset Pompe disease and is compound heterozygous for the variant and c.-32-13T>G, phase unknown (PMID 26873529). Based on this data, PM3 can be applied. Additional cases have been reported but were not included for PM3 because the residual GAA activity was not reported and therefore PP4 cannot be assessed (PMIDs 29523196, 27408821), full HGVS nomenclature was not provided (PMID 20033296), or the second variant is a variant of unknown significance (PMID 18607768). There is a ClinVar entry for this variant (Variation ID: 189041, 2 star review status) with 3 submitters classifying the variant and 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, PM3, PM2, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA274311/MONDO:0009290/010

• Frequency: Genomes: not found (cov: 33)
• Consequence: GAA NM_000152.5 frameshift, missense
• Clinical Significance: Pathogenic reviewed by expert panel P:8
• Conservation: PhyloP100: 9.37

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]

ACMG classification

Verdict is Pathogenic. Variant got 13 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.
• PM3: 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.1128_1129delGGinsC	p.Trp376CysfsTer16	frameshift_variant, missense_variant	Exon 7 of 20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8	c.1128_1129delGGinsC	p.Trp376CysfsTer16	frameshift_variant, missense_variant	Exon 7 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: reviewed by expert panel

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:6

Oct 28, 2014

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

Mar 11, 2025

Department of Human Genetics, Hannover Medical School

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinGen VCEP: PVS1, PM2_Supporting, PM3, PP4 -

Jan 07, 2019

Molecular Therapies Laboratory, Murdoch University

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Feb 14, 2020

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

This variant, c.1128_1129delGGinsC (p.Trp376Cysfs), 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 variant is absent in gnomAD v2.1.1, meeting PM2. Two individuals have been reported who meet the ClinGen LSD VCEP's specifications for PP4 and who are compound heterozygous for c.1128_1129delGGinsC (p.Trp376Cysfs) and a unique pathogenic variant in GAA; one individual has infantile-onset Pompe disease and is compound heterozygous for the variant and c.2237G>A (p.Trp746Ter), phase unknown (PMID 22237443), the second individual has late onset Pompe disease and is compound heterozygous for the variant and c.-32-13T>G, phase unknown (PMID 26873529). Based on this data, PM3 can be applied. Additional cases have been reported but were not included for PM3 because the residual GAA activity was not reported and therefore PP4 cannot be assessed (PMIDs 29523196, 27408821), full HGVS nomenclature was not provided (PMID 20033296), or the second variant is a variant of unknown significance (PMID 18607768). There is a ClinVar entry for this variant (Variation ID: 189041, 2 star review status) with 3 submitters classifying the variant and 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, PM3, PM2, PP4. -

Jul 04, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 14, 2024

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.Trp376Cysfs*16) 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). Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This premature translational stop signal has been observed in individuals with glycogen storage disease (PMID: 18425781, 18607768, 22252923, 22676651). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:2

Jan 11, 2023

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 03, 2017

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs786204646; hg19: chr17-78082340;