chr17-80113311-CTG-C

Variant names:

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

Variant summary

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

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

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.

• 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

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000232

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

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

Apr 24, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 14, 2018

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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). -

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

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: rs1555601780; hg19: chr17-78087110;