rs1057516581

Positions:

• chr17-80113360-TC-T

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PP4 PM2_Supporting PM3_Supporting PVS1

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.2185del (p.Leu729TrpfsTer35) variant in GAA is a frameshift variant predicted to cause a premature stop codon and to lead to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). This variant has been reported in three individuals with infantile onset Pompe disease (PMIDs 19588081, 24269976, 28394184)(PP4). One of these individuals is homozygous for the variant (PMID 19588081)(PM3_Supporting); another individual is heterozygous for the variant but a second variant was not found (PMID, 24269976), and one is compound heterozygous for the variant and c.1935C>A (p.Asp645Glu)(PMID 28394184). The allelic data for this latter patient was used in the assessment of p.Asp645Glu and is not included here to avoid circular logic. The variant is absent in gnomAD v2.1.1 (PM2_Supporting). There is a ClinVar entry for this variant (Variant ID 370552; 2 star review status) with one submitter 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 met, as specified by the ClinGen LSD VCEP (Specifications Version 2.0): PVS1, PP4, PM2_Supporting, PM3_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA16041899/MONDO:0009290/010

• Frequency: Genomes: not found (cov: 33)
• Consequence: GAA NM_000152.5 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:6
• Conservation: PhyloP100: 1.87

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 11 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GAA	NM_000152.5	c.2185del	p.Leu729TrpfsTer35	frameshift_variant	15/20	ENST00000302262.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GAA	ENST00000302262.8	c.2185del	p.Leu729TrpfsTer35	frameshift_variant	15/20	1	NM_000152.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: reviewed by expert panel

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:6

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 22, 2022	Variant summary: GAA c.2185delC (p.Leu729TrpfsX35) 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. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 199474 control chromosomes (gnomAD). c.2185delC has been reported in the literature in individuals affected with Glycogen Storage Disease, Type 2 (Pompe Disease) (Oba-Shinjo_2009, Fu_2013, Nio_2019). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four ClinVar submitters (evaluation after 2014) cite the variant as pathogenic (n=3) and likely pathogenic (n=1), including ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel classified it as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Aug 16, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 21, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Feb 26, 2016	- -
Pathogenic, reviewed by expert panel	curation	ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel	Nov 19, 2021	The NM_000152.5:c.2185del (p.Leu729TrpfsTer35) variant in GAA is a frameshift variant predicted to cause a premature stop codon and to lead to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). This variant has been reported in three individuals with infantile onset Pompe disease (PMIDs 19588081, 24269976, 28394184)(PP4). One of these individuals is homozygous for the variant (PMID 19588081)(PM3_Supporting); another individual is heterozygous for the variant but a second variant was not found (PMID, 24269976), and one is compound heterozygous for the variant and c.1935C>A (p.Asp645Glu)(PMID 28394184). The allelic data for this latter patient was used in the assessment of p.Asp645Glu and is not included here to avoid circular logic. The variant is absent in gnomAD v2.1.1 (PM2_Supporting). There is a ClinVar entry for this variant (Variant ID 370552; 2 star review status) with one submitter 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 met, as specified by the ClinGen LSD VCEP (Specifications Version 2.0): PVS1, PP4, PM2_Supporting, PM3_Supporting. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 16, 2022	This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Leu729Trpfs*35) 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 premature translational stop signal has been observed in individuals with glycogen storage disease (PMID: 19588081, 28394184). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 370552). -

Computational scores

Source: dbNSFP v4.3

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

Other links and lift over

dbSNP: rs1057516581; hg19: chr17-78087159;