17-80113311-CTG-C

Variant names:

• chr17-80113311-CTG-C
• rs1555601780
• NM_000152.5:c.2136_2137delGT

Variant summary

Our verdict is Pathogenic. The variant received 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.2136_2137del (p.Phe713ProfsTer23) variant in GAA is a frameshift variant predicted to cause a premature stop codon in biologically-relevant-exon 15/20, predicted to lead to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). A patient with this variant was reported to have deficient GAA activity and to be on enzyme replacement therapy for Pompe disease (PMID:25614309, 27896092)(PP4). This patient is compound heterozygous, phase unknown, for the variant and a pathogenic variant in GAA, c.-32-13T>G ( PMID:25614309, 27896092)(PM3_Supporting). There is a ClinVar entry for this variant (Variation ID: 556718; 1 star review status) with one submitter classifying the variant as likely pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria met, based on the specifications of the ClinGen Lysosomal Storage Disorders VCEP (Specification Version 2.0): PVS1, PM2_Supporting, PM3_Supporting, PP4.(Classification approved on August 17th, 2021) LINK:https://erepo.genome.network/evrepo/ui/classification/CA658795274/MONDO:0009290/010

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GAA NM_000152.5 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:4
• Conservation: PhyloP100: 6.08
• Publications: 0 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.
• 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.2136_2137delGT	p.Phe713ProfsTer23	frameshift_variant	Exon 15 of 20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8	c.2136_2137delGT	p.Phe713ProfsTer23	frameshift_variant	Exon 15 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.91e-7 AC: 1 AN: 1447030 Hom.: 0 AF XY: 0.00000139 AC XY: 1 AN XY: 718462

African (AFR) AF: 0.00 AC: 0 AN: 33240

American (AMR) AF: 0.0000232 AC: 1 AN: 43062

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25696

East Asian (EAS) AF: 0.00 AC: 0 AN: 38960

South Asian (SAS) AF: 0.00 AC: 0 AN: 83492

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51966

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5742

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1105098

Other (OTH) AF: 0.00 AC: 0 AN: 59774

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: reviewed by expert panel

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:4

Nov 27, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This premature translational stop signal has been observed in individual(s) with Pompe disease (PMID: 25614309). This variant is also known as c.2136-7delGT. ClinVar contains an entry for this variant (Variation ID: 556718). For these reasons, this variant has been classified as Pathogenic. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Phe713Profs*23) 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). -

Feb 14, 2018

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

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. -

Apr 24, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 19, 2021

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000152.5:c.2136_2137del (p.Phe713ProfsTer23) variant in GAA is a frameshift variant predicted to cause a premature stop codon in biologically-relevant-exon 15/20, predicted to lead to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). A patient with this variant was reported to have deficient GAA activity and to be on enzyme replacement therapy for Pompe disease (PMID: 25614309, 27896092)(PP4). This patient is compound heterozygous, phase unknown, for the variant and a pathogenic variant in GAA, c.-32-13T>G ( PMID: 25614309, 27896092)(PM3_Supporting). There is a ClinVar entry for this variant (Variation ID: 556718; 1 star review status) with one submitter classifying the variant as likely pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria met, based on the specifications of the ClinGen Lysosomal Storage Disorders VCEP (Specification Version 2.0): PVS1, PM2_Supporting, PM3_Supporting, PP4. (Classification approved on August 17th, 2021) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		6.1
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: rs1555601780; hg19: chr17-78087110;