rs779556619

Variant names:

• chr17-80112001-T-C
• rs779556619
• NM_000152.5:c.1655T>C

Variant summary

Our verdict is Pathogenic. The variant received 8 ACMG points: 8P and 0B. PP3 PM2_Supporting PS3_Moderate PM3 PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The NM_000152.5: c.1655T>C variant in GAA is a missense variant predicted to cause substitution of leucine by proline at amino acid 552 (p.Leu552Pro). More than 10 individuals diagnosed with Pompe disease have been reported with this variant including at least 7 probands for whom laboratory data is published showing GAA activity in the deficient range (PMID 12923862, 18285536, 25681614, 27666774)(PP4_Moderate). Eight of these individuals were compound heterozygous for the variant and a pathogenic variant, phase unknown in all cases (PMID 12923862, 18285536, 18607768, 20033296, 25681614, 29122469 29422078, and two individuals were homozygotes (PMID 27666774)(PM3_Very strong). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00007 (European non-Finnish) which is lower than the ClinGen LSD VCEP threshold (<0.001) for PM2_Supporting. In two functional studies, this variant has been shown to result in significantly decreased GAA activity (<5%) and abnormal processing when expressed in COS cells (PMIDs 14695532, 19862843)(PS3_Moderate). The computational predictor REVEL gives a score of 0.94, 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: 279811, 2 star review status) with nine submitters all classifying the variant as pathogenic. In summary, the variant meets the criteria to be classified as pathogenic for Pompe disease. ACMG/AMP criteria met, as specified by the ClinGen LSD VCEP (Specifications Version 2.0): PM3_Very Strong, PS3_Moderate, PP4_Moderate, PM2_Supporting, PP3.(Classification approved August 17, 2021) LINK:https://erepo.genome.network/evrepo/ui/classification/CA8815429/MONDO:0009290/010

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000028 (0 hom.)
• Consequence: GAA NM_000152.5 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:19 O:1
• Conservation: PhyloP100: 7.44
• Publications: 43 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: Pathogenic. The variant received 8 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	NM_000152.5	MANE Select	c.1655T>C	p.Leu552Pro	missense	Exon 12 of 20	NP_000143.2	P10253
	GAA	NM_001079803.3		c.1655T>C	p.Leu552Pro	missense	Exon 13 of 21	NP_001073271.1	P10253
	GAA	NM_001079804.3		c.1655T>C	p.Leu552Pro	missense	Exon 12 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.1655T>C	p.Leu552Pro	missense	Exon 12 of 20	ENSP00000305692.3	P10253
	GAA	ENST00000390015.7	TSL:1	c.1655T>C	p.Leu552Pro	missense	Exon 13 of 21	ENSP00000374665.3	P10253
	GAA	ENST00000933406.1		c.1670T>C	p.Leu557Pro	missense	Exon 12 of 20	ENSP00000603465.1

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152102 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000735

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000319 AC: 8 AN: 250910 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000705

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000281 AC: 41 AN: 1461506 Hom.: 0 Cov.: 31 AF XY: 0.0000248 AC XY: 18 AN XY: 727106

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53206

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

European-Non Finnish (NFE) AF: 0.0000342 AC: 38 AN: 1111890

Other (OTH) AF: 0.0000497 AC: 3 AN: 60382

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152102 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74300

African (AFR) AF: 0.00 AC: 0 AN: 41404

American (AMR) AF: 0.00 AC: 0 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000735 AC: 5 AN: 67990

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000827 Hom.: 0

Bravo AF: 0.0000302

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.000109

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
11	-	-	Glycogen storage disease, type II (12)
7	-	-	not provided (7)
1	-	-	GAA-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.88	D
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	1.0	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.0	H
PhyloP100		7.4
PrimateAI	Uncertain	0.56	T
PROVEAN	Pathogenic	-6.4	D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.90		Gain of sheet (P = 0.039)
MVP		1.0
MPC		0.69
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.95
gMVP		0.98
Mutation Taster		=12/88	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs779556619; hg19: chr17-78085800;