17-80110953-C-G

Variant names:

• chr17-80110953-C-G
• rs892129065
• NM_000152.5:c.1564C>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PP3 PM2_Supporting PM3_Strong PM5_Supporting PS3_Supporting PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.1564C>G variant in GAA is a missense variant predicted to cause substitution of proline by alanine at amino acid 522 (p.Pro522Ala). This variant has been detected in at least 7 unrelated patients reported to have Pompe disease including four individuals with reported laboratory values demonstrating deficient GAA activity (PMID:26800218, 33301762, 34072668, Duke University), and three for whom GAA activity was not reported (PMID:18429042, 37087815) (PP4_Moderate). Of those individuals, 6 were compound heterozygous for the variant and a variant classified as pathogenic by the ClinGen LD VCEP: c.784G>A (p.Glu262Lys) (ClinVar Variation ID: 188806, SCV002032128.1) (PMID:18429042), c.1933G>A (p.Asp645Asn) (ClinVar Variation ID: 188728, SCV001371736.1) (PMID:18429042), c.1465G>A (p.Asp489Asn) (ClinVar Variation ID: 92465, SCV003852732.1) (PMID:34072668), and c.-32-13T>G (ClinVar Variation ID: 4027) (PMID:26800218, 37087815, Clinical Diagnostic Laboratory; at least 3 unrelated patients). The phase is not confirmed for any of these individuals. One individual was homozygous for this variant (PMID:33301762) (PM3_Strong). Another missense variant, c.1564C>T, p.Pro522Ser (ClinVar Variation ID: 972746) in the same codon has been classified as likely pathogenic for Pompe disease by the ClinGen Lysosomal Diseases VCEP (PM5_Supporting). This variant is absent in gnomAD v2.1.1 (PM2_Supporting). Expression of the variant in Ad5-SV40 immortalized human GAA-deficient fibroblast cell line resulted in 0% wild type GAA activity when measured using fluorogenic substrate 4-methylumbelliferyl-α-D glucopyranoside. This was further supported via Western blot analysis demonstrating deficient GAA protein expression (PMID:18429042) (PS3_Supporting). The computational predictor REVEL gives a score of 0.883 which is above the threshold predicting a damaging (>0.7) impact on GAA function. There is a ClinVar entry for this variant (Variation ID: 371277). 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 Diseases VCEP (Specifications Version 2.0): PM3_Strong, PP4_Moderate, PM2_Supporting, PM5_Supporting PS3_Supporting.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on March 19, 2024). LINK:https://erepo.genome.network/evrepo/ui/classification/CA16041893/MONDO:0009290/010

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GAA NM_000152.5 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:10
• Conservation: PhyloP100: 6.02
• Publications: 3 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.
• PM5: 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	NM_000152.5	MANE Select	c.1564C>G	p.Pro522Ala	missense	Exon 11 of 20	NP_000143.2
	GAA	NM_001079803.3		c.1564C>G	p.Pro522Ala	missense	Exon 12 of 21	NP_001073271.1
	GAA	NM_001079804.3		c.1564C>G	p.Pro522Ala	missense	Exon 11 of 20	NP_001073272.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	ENST00000302262.8	TSL:1 MANE Select	c.1564C>G	p.Pro522Ala	missense	Exon 11 of 20	ENSP00000305692.3
	GAA	ENST00000390015.7	TSL:1	c.1564C>G	p.Pro522Ala	missense	Exon 12 of 21	ENSP00000374665.3
	GAA	ENST00000933406.1		c.1579C>G	p.Pro527Ala	missense	Exon 11 of 20	ENSP00000603465.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461636 Hom.: 0 Cov.: 36 AF XY: 0.00000138 AC XY: 1 AN XY: 727104

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44710

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53238

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111960

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
6	-	-	Glycogen storage disease, type II (6)
4	-	-	not provided (4)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.65
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.40
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.4	M
PhyloP100		6.0
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-7.6	D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.025	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.90
MutPred		0.97		Loss of disorder (P = 0.0763)
MVP		1.0
MPC		0.53
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.86
gMVP		0.92
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
Splicevardb		2.0
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: rs892129065; hg19: chr17-78084752;