rs753269119

chr17-80112679-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000152.5(GAA):c.1856G>A(p.Ser619Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,611,154 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S619R) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: GAA NM_000152.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11
• Conservation: PhyloP100: 7.79

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000152.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-80112680-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 550825.Status of the report is reviewed_by_expert_panel, 3 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant 17-80112679-G-A is Pathogenic according to our data. Variant chr17-80112679-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 370146.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-80112679-G-A is described in Lovd as [Pathogenic]. Variant chr17-80112679-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GAA	NM_000152.5	c.1856G>A	p.Ser619Asn	missense_variant	13/20	ENST00000302262.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GAA	ENST00000302262.8	c.1856G>A	p.Ser619Asn	missense_variant	13/20	1	NM_000152.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152036 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: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000166 AC: 4 AN: 241268 Hom.: 0 AF XY: 0.0000152 AC XY: 2 AN XY: 131764

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 SAS exome AF: 0.000133

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000117 AC: 17 AN: 1458998 Hom.: 0 Cov.: 33 AF XY: 0.0000165 AC XY: 12 AN XY: 725696

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000175

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152156 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74388

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000414

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ExAC AF: 0.0000330 AC: 4

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:11

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:8

Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Apr 10, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 10, 2019	Variant summary: GAA c.1856G>A (p.Ser619Asn) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.7e-05 in 237486 control chromosomes (gnomAD). The variant, c.1856G>A, has been reported in the literature in individuals affected with Glycogen Storage Disease, Type 2 (Pompe Disease)(Kroos_2006, Remiche_2014, Gallardo_2011, Parenti_2014, Arslan_2016). One patient, Arslan_2016, was found to be homozygous for two deleterious variants, the variant of interest and c.32-13T>G, to which the authors indicate the phenotype was more progressive. The patient was born to consanguineous Turkish parents. These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of residual acid -glucosidase activity (Kroos_2006). A ClinVar submission from a clinical diagnostic laboratory (evaluation after 2014) cites the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Nov 30, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 20, 2024	This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 619 of the GAA protein (p.Ser619Asn). This variant is present in population databases (rs753269119, gnomAD 0.01%). This missense change has been observed in individual(s) with Pompe disease (PMID: 16838077, 22990675, 24158270, 25998610, 26946079). ClinVar contains an entry for this variant (Variation ID: 370146). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GAA protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GAA function (PMID: 19862843). This variant disrupts the p.Ser619 amino acid residue in GAA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 14643388, 21471980, 25213570, 27363342, 29124014). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Nov 03, 2022	The p.Ser619Asn variant in GAA has been reported in at least 8 individuals (6 in the compound heterozygous state) with Glycogen Storage Disease II. Of note, in 2 of these individuals (one homozygote and one compound heterozygote), this variant was in cis with the known pathogenic variant c.-32-13T>G (Gallardo 2011 PMID: 22194990, Arslan 2016 PMID: 26946079, Alejaldre 2012 PMID: 22980766, Kroos 2006 PMID: 16838077, Remiche 2014 PMID: 24158270, Parenti 2014 PMID: 25052852, Fecarotta 2013 PMID: 23668440, Gutiérrez-Rivas 2015 PMID: 25998610). This variant has also been reported in ClinVar (Variation ID: 370146) and has been identified in 2/4830 of South Asian and 1/67968 of European chromosomes by gnomAD (http://gnomad.broadinstitute.org). In vitro functional studies using patient tissues provide some evidence that this variant may impact proteolytic activation of GAA and GAA activity (Kroos 2006 PMID: 16838077). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. Another variant involving this codon (p.Ser619Arg) has been identified in individuals with autosomal recessive Glycogen Storage Disease II and is classified as likely pathogenic/pathogenic in ClinVar. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive Glycogen Storage Disease II. ACMG/AMP Criteria applied: PS3_Moderate, PM2_Supporting, PM5, PP3, PM3_Very strong. -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Feb 17, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jul 06, 2023	- -
Pathogenic, criteria provided, single submitter	curation	Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard	Jan 22, 2020	The p.Ser619Asn variant in GAA has been reported in 8 individuals with Glycogen Storage Disease II (PMID: 22194990, 26946079, 22980766, 16838077, 24158270, 25052852, 23668440, 25998610). This variant has also been reported likely pathogenic by Counsyl in ClinVar (Variation ID: 370146) and has been identified in 0.013% (4/29974) of South Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs753269119). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. In vitro functional studies provide some evidence that the p.Ser619Asn variant may impact proteolytic activation of GAA and GAA activity (PMID: 16838077, 19862843). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. One pathogenic additional variant at the the same position, p.Ser619Arg, has been reported in association with disease in ClinVar, supporting that a change at this position may not be tolerated (Variation ID: 550825). The presence of this variant in combination with a pathogenic variant and in an individual with Glycogen Storage Disease II increases the likelihood that the p.Ser619Asn variant is pathogenic (PMID: 16838077). Of note, this variant has also been observed in cis with the known pathogenic variant c.-32-13T>G with both variants in the homozygous state in an individual with Glycogen Storage Disorder II (PMID: 26946079). The phenotype of individuals homozygous and heterozygous for this variant is highly specific for Glycogen Storage Disease II based on reduced GAA activity in relevant tissue, consistent with disease (PMID: 24158270, 26946079, 16838077). In summary, this variant meets criteria to be classified as pathogenic for Glycogen Storage Disease II in an autosomal recessive manner based on in vitro functional studies, another pathogenic variant at the same position, and low frequency in the general population. ACMG/AMP Criteria applied: PS3, PM2, PM5, PP3, PM3_Supporting, PP4 (Richards 2015). -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Aug 16, 2023	- -

Abnormality of metabolism/homeostasis Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Kariminejad - Najmabadi Pathology & Genetics Center

Jul 10, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.78
BayesDel_addAF	Uncertain	0.047	T
BayesDel_noAF	Uncertain	0.070
Cadd	Pathogenic	28
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;D
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.9	H;H
MutationTaster	Benign	0.99	D;D
PrimateAI	Uncertain	0.55	T
PROVEAN	Uncertain	-2.9	D;D
REVEL	Pathogenic	0.74
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	D;D
Vest4		0.95
MutPred		0.98		Loss of disorder (P = 0.1076);Loss of disorder (P = 0.1076);
MVP		1.0
MPC		0.52
ClinPred		0.99	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.94
gMVP		0.94

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

Publications

LitVar

Other links and lift over

dbSNP: rs753269119; hg19: chr17-78086478;