NM_000152.5:c.236_246delCCACACAGTGC

Variant names:

• chr17-80104815-GCAGTGCCCACA-G
• rs1057517165
• NM_000152.5:c.236_246delCCACACAGTGC

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PP4 PM3 PVS1 PM2

This summary comes from the ClinGen Evidence Repository: This variant, c.236_246del (p.Pro79ArgfsTer13), has been reported in multiple patients with Pompe disease. For two of these patients, residual GAA activity is reported and meets the ClinGen LSD VCEP's specifications for PP4 (PMID 17056254, 30778879). Both of these patients are compound heterozygous for the variant and a unique pathogenic variant; one with c.377G>A (p.Trp126Ter), in trans (PMID 17056254), and the other with c.1655T>C (p.Leu552Pro), phase unknown (PMID 30778879). This data meets PM3. Additional cases, both homozygous and compound heterozygous, have been reported but were not included because the residual GAA activity was not provided, and therefore PP4 cannot be assessed (PMIDs, 19588081, 22194990, 22980766, 23825616, 25998610, 26913919, 29143201, 30022036, 32125626). There is a ClinVar entry for this variant (Variation ID: 371302, 1 star review status) with 1 submitter classifying the variant as 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, PM3, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA16041880/MONDO:0009290/010

• Frequency: Genomes: not found (cov: 32)
• Consequence: GAA NM_000152.5 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:4
• Conservation: PhyloP100: 1.82
• Publications: 13 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 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.236_246delCCACACAGTGC	p.Pro79ArgfsTer13	frameshift_variant	Exon 2 of 20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8	c.236_246delCCACACAGTGC	p.Pro79ArgfsTer13	frameshift_variant	Exon 2 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes Cov.: 32

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

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: reviewed by expert panel

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:4

Jan 22, 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.Pro79Argfs*13) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Pompe disease (PMID: 17056254). ClinVar contains an entry for this variant (Variation ID: 371302). For these reasons, this variant has been classified as Pathogenic. -

Aug 23, 2016

Counsyl

Significance: 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. -

Jun 16, 2020

ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

This variant, c.236_246del (p.Pro79ArgfsTer13), has been reported in multiple patients with Pompe disease. For two of these patients, residual GAA activity is reported and meets the ClinGen LSD VCEP's specifications for PP4 (PMID 17056254, 30778879). Both of these patients are compound heterozygous for the variant and a unique pathogenic variant; one with c.377G>A (p.Trp126Ter), in trans (PMID 17056254), and the other with c.1655T>C (p.Leu552Pro), phase unknown (PMID 30778879). This data meets PM3. Additional cases, both homozygous and compound heterozygous, have been reported but were not included because the residual GAA activity was not provided, and therefore PP4 cannot be assessed (PMIDs, 19588081, 22194990, 22980766, 23825616, 25998610, 26913919, 29143201, 30022036, 32125626). There is a ClinVar entry for this variant (Variation ID: 371302, 1 star review status) with 1 submitter classifying the variant as 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, PM3, PP4. -

Jan 18, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.8
Mutation Taster		=6/194	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs1057517165; hg19: chr17-78078614;