rs778068209

Variant names:

• chr17-80110050-G-A
• rs778068209
• NM_000152.5:c.1432G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PP3 PM2_Supporting PS3_Moderate PM3_Strong PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.1432G>A variant in GAA is a missense variant predicted to cause substitution of glycine by arginine at amino acid 478 (p.Gly478Arg). At least seven probands with symptoms consistent with infantile-onset-Pompe disease or late-onset Pompe disease with documented deficiency of GAA activity have been reported with this variant (PMIDs 25998610, 25213570, 17616415, 28394184) (PP4_Moderate). Six of these probands are compound heterozygous for the variant and a variant classified as pathogenic by the ClinGen Lysosomal Diseases VCEP; the variants were confirmed in trans by parental testing for one of the patients (PM3_Strong). The highest population minor allele frequency in gnomAD v2.1,1 is 0.00002895 (Latino) which is lower than the ClinGen LSD VCEP threshold (<0.001) for PM2_supporting, meeting this criterion. Expression of the variant in COS7 cells resulted in <2% GAA activity in cells, indicating that this variant may impact protein function (PMID 22253258, 19862843) (PS3_Moderate). The computational predictor REVEL gives a score of 0.954 which is above the threshold of 0.7, evidence that correlates with impact to GAA function (PP3). There is a ClinVar entry for this variant (Variation ID: 551295, 2 star review status) with 2 submitters classifying the variant as Likely Pathogenic and 2 submitters classfying the variant as Pathogenic. In summary, this variant meets the criteria to be classified as Pathogenic for Pompe disease based on the ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert panel (specifications Version 2.0): PM3_Strong, PP4_Moderate, PS3_Moderate, PP3, PM2_Supporting.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on November 5, 2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA8815317/MONDO:0009290/010

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GAA NM_000152.5 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:7
• Conservation: PhyloP100: 9.34
• Publications: 14 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.

• PS3: 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.
• PP3: 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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	NM_000152.5	MANE Select	c.1432G>A	p.Gly478Arg	missense	Exon 9 of 20	NP_000143.2
	GAA	NM_001079803.3		c.1432G>A	p.Gly478Arg	missense	Exon 10 of 21	NP_001073271.1
	GAA	NM_001079804.3		c.1432G>A	p.Gly478Arg	missense	Exon 9 of 20	NP_001073272.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	ENST00000302262.8	TSL:1 MANE Select	c.1432G>A	p.Gly478Arg	missense	Exon 9 of 20	ENSP00000305692.3
	GAA	ENST00000390015.7	TSL:1	c.1432G>A	p.Gly478Arg	missense	Exon 10 of 21	ENSP00000374665.3
	GAA	ENST00000570803.6	TSL:5	c.1432G>A	p.Gly478Arg	missense	Exon 9 of 20	ENSP00000460543.2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD2 exomes AF: 0.00000402 AC: 1 AN: 248486 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460582 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726636

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.0000224 AC: 1 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52632

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111572

Other (OTH) AF: 0.00 AC: 0 AN: 60358

GnomAD4 genome Cov.: 34

Alfa AF: 0.000145 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
7	-	-	Glycogen storage disease, type II (7)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.55	D
MetaRNN	Pathogenic	1.0	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.2	H
PhyloP100		9.3
PrimateAI	Pathogenic	0.79	T
PROVEAN	Pathogenic	-7.9	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.94		Loss of ubiquitination at K479 (P = 0.059)
MVP		1.0
MPC		0.59
ClinPred		1.0	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.97
gMVP		0.98
Mutation Taster		=2/98	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: rs778068209; hg19: chr17-78083849;