rs1555599594

Variant names:

• chr17-80107579-CT-C
• rs1555599594
• NM_000152.5:c.716delT

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PP4 PM2 PVS1

This summary comes from the ClinGen Evidence Repository: This variant, c.716delT (p.Leu239ArgfsTer29), is a frameshift variant that is predicted to result in a premature termination codon, nonsense mediated decay, and lack of gene product, meeting PVS1. One patient with this variant meets the ClinGen LSD VCEP’s specifications for PP4. This patient is compound heterozygous for the variant and c.1447G>A (p.Gly483Arg) (PMID 31606152, personal communication). This in trans data will be used in the assessment of p.Gly483Arg and is not included here in order to avoid circular logic. Another patient who is compound heterozygous for the variant has been reported (PMID 14695532). However, residual GAA activity was not provided and this data was not included. Therefore, PM3 is not currently met. This variant is not in gnomAD v2.1.1, meeting PM2. There is a ClinVar entry for this variant (Variation ID: 556853, 2 star review status) with one submitter classifying the variant as pathogenic and two as likely 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, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA658795234/MONDO:0009290/010

• Frequency: Genomes: not found (cov: 34)
• Consequence: GAA NM_000152.5 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:6
• Conservation: PhyloP100: 7.88
• 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: PanelApp Australia, Laboratory for Molecular Medicine, ClinGen, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
• 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.
• PP4: 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.716delT	p.Leu239ArgfsTer29	frameshift	Exon 4 of 20	NP_000143.2	P10253
	GAA	NM_001079803.3		c.716delT	p.Leu239ArgfsTer29	frameshift	Exon 5 of 21	NP_001073271.1	P10253
	GAA	NM_001079804.3		c.716delT	p.Leu239ArgfsTer29	frameshift	Exon 4 of 20	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.716delT	p.Leu239ArgfsTer29	frameshift	Exon 4 of 20	ENSP00000305692.3	P10253
	GAA	ENST00000390015.7	TSL:1	c.716delT	p.Leu239ArgfsTer29	frameshift	Exon 5 of 21	ENSP00000374665.3	P10253
	GAA	ENST00000933406.1		c.716delT	p.Leu239ArgfsTer29	frameshift	Exon 4 of 20	ENSP00000603465.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 34

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
4	-	-	Glycogen storage disease, type II (4)
2	-	-	not provided (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.9
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: rs1555599594; hg19: chr17-78081378;