17-80104166-AAGTGGGAGGATTGCTTGAGTCTGGGAGGTGGAGGTTGCAGTGAGCCAGGATCTCACCACAGCACTCTGGCCCAGGCGACAGCTGTTTGGCCTGTTTCAAGTGTCTACCTGCCTTGCTGGTCTTCCTGGGGACATTCTAAGCGTGTTTGATTTGTAACATTTTAGCAGACTGTGCAAGTGCTCTGCACTCCCCTGCTGGAGCTTTTCTCGCCCTTCCTTCTGGCCCTCTCCCCAGTCTAGACAGCAGGGCAACACCCACCCTGGCCACCTTACCCCACCTGCCTGGGTGCTGCAGTGCCAGCCGCGGTTGATGTCTCAGAGCTGCTTTGAGAGCCCCGTGAGTGCCGCCCCTCCCGCCTCCCTGCTGAGCCCGCTTTCTTCTCCCGCAGGCCTGTAGGAGCTGTCCAGGCCATCTCCAACCATGGGAGTGAGGCACCCGCCCTGCTCCCACCGGCTCCTGGCCGTCTGCGCCCTCGTGTCCTTGGCAACCGCTGCACTCCTGGGGCACATCCTACTCCATGATTTCCTGCTGGTTCCCCGAGAGCTGAGTGGCTCCTCCCC-A

Variant names:

• chr17-80104166-AAGTGGGAGGATTGCTTGAGTCTGGGAGGTGGAGGTTGCAGTGAGCCAGGATCTCACCACAGCACTCTGGCCCAGGCGACAGCTGTTTGGCCTGTTTCAAGTGTCTACCTGCCTTGCTGGTCTTCCTGGGGACATTCTAAGCGTGTTTGATTTGTAACATTTTAGCAGACTGTGCAAGTGCTCTGCACTCCCCTGCTGGAGCTTTTCTCGCCCTTCCTTCTGGCCCTCTCCCCAGTCTAGACAGCAGGGCAACACCCACCCTGGCCACCTTACCCCACCTGCCTGGGTGCTGCAGTGCCAGCCGCGGTTGATGTCTCAGAGCTGCTTTGAGAGCCCCGTGAGTGCCGCCCCTCCCGCCTCCCTGCTGAGCCCGCTTTCTTCTCCCGCAGGCCTGTAGGAGCTGTCCAGGCCATCTCCAACCATGGGAGTGAGGCACCCGCCCTGCTCCCACCGGCTCCTGGCCGTCTGCGCCCTCGTGTCCTTGGCAACCGCTGCACTCCTGGGGCACATCCTACTCCATGATTTCCTGCTGGTTCCCCGAGAGCTGAGTGGCTCCTCCCC-A
• NM_000152.5:c.-32-385_143del

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PP5_Moderate

The NM_000152.5(GAA):​c.-32-385_143del variant causes a splice acceptor, 5 prime UTR truncation, exon loss, splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GAA NM_000152.5 splice_acceptor, 5_prime_UTR_truncation, exon_loss, splice_region, intron
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.50
• 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 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PP5: Variant 17-80104166-AAGTGGGAGGATTGCTTGAGTCTGGGAGGTGGAGGTTGCAGTGAGCCAGGATCTCACCACAGCACTCTGGCCCAGGCGACAGCTGTTTGGCCTGTTTCAAGTGTCTACCTGCCTTGCTGGTCTTCCTGGGGACATTCTAAGCGTGTTTGATTTGTAACATTTTAGCAGACTGTGCAAGTGCTCTGCACTCCCCTGCTGGAGCTTTTCTCGCCCTTCCTTCTGGCCCTCTCCCCAGTCTAGACAGCAGGGCAACACCCACCCTGGCCACCTTACCCCACCTGCCTGGGTGCTGCAGTGCCAGCCGCGGTTGATGTCTCAGAGCTGCTTTGAGAGCCCCGTGAGTGCCGCCCCTCCCGCCTCCCTGCTGAGCCCGCTTTCTTCTCCCGCAGGCCTGTAGGAGCTGTCCAGGCCATCTCCAACCATGGGAGTGAGGCACCCGCCCTGCTCCCACCGGCTCCTGGCCGTCTGCGCCCTCGTGTCCTTGGCAACCGCTGCACTCCTGGGGCACATCCTACTCCATGATTTCCTGCTGGTTCCCCGAGAGCTGAGTGGCTCCTCCCC-A is Pathogenic according to our data. Variant chr17-80104166-AAGTGGGAGGATTGCTTGAGTCTGGGAGGTGGAGGTTGCAGTGAGCCAGGATCTCACCACAGCACTCTGGCCCAGGCGACAGCTGTTTGGCCTGTTTCAAGTGTCTACCTGCCTTGCTGGTCTTCCTGGGGACATTCTAAGCGTGTTTGATTTGTAACATTTTAGCAGACTGTGCAAGTGCTCTGCACTCCCCTGCTGGAGCTTTTCTCGCCCTTCCTTCTGGCCCTCTCCCCAGTCTAGACAGCAGGGCAACACCCACCCTGGCCACCTTACCCCACCTGCCTGGGTGCTGCAGTGCCAGCCGCGGTTGATGTCTCAGAGCTGCTTTGAGAGCCCCGTGAGTGCCGCCCCTCCCGCCTCCCTGCTGAGCCCGCTTTCTTCTCCCGCAGGCCTGTAGGAGCTGTCCAGGCCATCTCCAACCATGGGAGTGAGGCACCCGCCCTGCTCCCACCGGCTCCTGGCCGTCTGCGCCCTCGTGTCCTTGGCAACCGCTGCACTCCTGGGGCACATCCTACTCCATGATTTCCTGCTGGTTCCCCGAGAGCTGAGTGGCTCCTCCCC-A is described in ClinVar as [Pathogenic]. Clinvar id is 2745468.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAA	NM_000152.5	c.-32-385_143del	p.Met1fs	frameshift_variant, start_lost, splice_region_variant	Exon 2 of 20	ENST00000302262.8	NP_000143.2
GAA	NM_000152.5	c.-32-385_143del		splice_acceptor_variant, 5_prime_UTR_truncation, exon_loss_variant, splice_region_variant, intron_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.-32-388_140del	p.Met1fs	frameshift_variant, start_lost, splice_region_variant	Exon 2 of 20	1	NM_000152.5	ENSP00000305692.3
GAA	ENST00000302262.8	c.-32-388_140del		splice_acceptor_variant, 5_prime_UTR_truncation, exon_loss_variant, splice_region_variant, intron_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

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:1

Jul 19, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the GAA protein in which other variant(s) (p.Met1?) have been determined to be pathogenic (PMID: 18425781, 22252923, 29124014, 29422078, 31086307). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. This variant has not been reported in the literature in individuals affected with GAA-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change affects the initiator methionine of the GAA mRNA. The next in-frame methionine is located at codon 122. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.5

Splicing

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

Other links and lift over

hg19: chr17-78077965;