rs1555601773

Variant names:

• chr17-80113309-CA-GG
• rs1555601773
• NM_000152.5:c.2132_2133delCAinsGG

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.2132_2133delinsGG variant in GAA is a multinucleotide variant predicted to cause substitution of threonine by arginine at amino acid 711 (p.Thr711Arg). The same amino acid change, resulting from one of the two nucleotide changes observed in this multinucleotide variant, c.2132C>G, has been reported in a patient with Pompe disease (PMID:20080426, 31342611). However, this other variant has conflicting evidence for pathogenicity based on guidelines by the ClinGen LSD VCEP (PMID:18425781). The minor allele frequency of the c.2132C>G variant in gnomAD v2.1.1 is 0.001258 (23/18290 alleles) in the East Asian population, but was only seen in phase with c.2133A>G in 23 of the 24 heterozygotes reported in gnomAD v2.1.1. Therefore, the highest possible population minor allele frequency in gnomAD v2.1.1 is 0.001258 (23/18290 alleles) in the East Asian population (none of the population data codes are met). The computational predictors PROVEAN, Mutation Taster, and MutPredIndel suggest that this variant has a deleterious effect on the GAA gene, evidence that correlates with impact to GAA function (PP3). To our knowledge, the results of functional assays have not been reported for this variant. There is a ClinVar entry for this variant (Variation ID: 456391, 1 star review status) with 2 submitters, 1 submitter classifying the variant as likely pathogenic and 1 submitter classifying the variant as a variant of uncertain significance. In summary, this variant meets the criteria to be classified as a variant of uncertain significance for Pompe disease based on the ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Storage Disorders Variant Curation Expert panel (specifications Version 2.0): PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA658658713/MONDO:0009290/010

• Frequency: GnomAD MNV: 𝑓 0.000092 Genomes: not found (cov: 33)
• Consequence: GAA NM_000152.5 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:1 U:3
• Conservation: PhyloP100: 4.87
• Publications: 2 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, ClinGen, Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine
• 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: Uncertain_significance. The variant received 1 ACMG points.

• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000152.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	NM_000152.5	MANE Select	c.2132_2133delCAinsGG	p.Thr711Arg	missense	N/A	NP_000143.2	P10253
	GAA	NM_001079803.3		c.2132_2133delCAinsGG	p.Thr711Arg	missense	N/A	NP_001073271.1	P10253
	GAA	NM_001079804.3		c.2132_2133delCAinsGG	p.Thr711Arg	missense	N/A	NP_001073272.1	P10253

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	ENST00000302262.8	TSL:1 MANE Select	c.2132_2133delCAinsGG	p.Thr711Arg	missense	N/A	ENSP00000305692.3	P10253
	GAA	ENST00000390015.7	TSL:1	c.2132_2133delCAinsGG	p.Thr711Arg	missense	N/A	ENSP00000374665.3	P10253
	GAA	ENST00000933406.1		c.2147_2148delCAinsGG	p.Thr716Arg	missense	N/A	ENSP00000603465.1

Frequencies

GnomAD3 genomes Cov.: 33

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

GnomAD4 genome Cov.: 33

GnomAD MNV AF: 0.0000917 AC: 23 Hom.: 0

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
1	1	-	Glycogen storage disease, type II (2)
-	1	-	not provided (1)
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		4.9

Splicing

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

Other links and lift over

dbSNP: rs1555601773; hg19: chr17-78087108;