17-80105865-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_StrongBP6BP7

The NM_000152.5(GAA):c.663C>T(p.Ile221Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000804 in 1,603,826 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. I221I) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00015 ( 0 hom., cov: 34)

Exomes 𝑓: 0.000073 ( 0 hom. )

Consequence

GAA
NM_000152.5 synonymous

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:4

Conservation

PhyloP100: -1.64

Publications

5 publications found

Variant links:

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

GAA links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -6 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.64).

BP6

Variant 17-80105865-C-T is Benign according to our data. Variant chr17-80105865-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 456426.

BP7

Synonymous conserved (PhyloP=-1.64 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAA	NM_000152.5 link	c.663C>T	p.Ile221Ile	synonymous_variant	Exon 3 of 20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8 link	c.663C>T	p.Ile221Ile	synonymous_variant	Exon 3 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes

AF:

0.000151

AC:

AN:

152222

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.000753

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000162

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000123

AC:

AN:

244200

AF XY:

0.000143

show subpopulations

Gnomad AFR exome

AF:

0.0000620

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000680

Gnomad NFE exome

AF:

0.000116

Gnomad OTH exome

AF:

0.000330

GnomAD4 exome

AF:

0.0000730

AC:

106

AN:

1451604

Hom.:

Cov.:

AF XY:

0.0000804

AC XY:

AN XY:

721772

show subpopulations

African (AFR)

AF:

0.0000898

AC:

AN:

33410

American (AMR)

AF:

0.0000224

AC:

AN:

44692

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26096

East Asian (EAS)

AF:

0.0000505

AC:

AN:

39624

South Asian (SAS)

AF:

0.000174

AC:

AN:

86206

European-Finnish (FIN)

AF:

0.000151

AC:

AN:

46444

Middle Eastern (MID)

AF:

0.000186

AC:

AN:

5362

European-Non Finnish (NFE)

AF:

0.0000604

AC:

AN:

1109596

Other (OTH)

AF:

0.000166

AC:

AN:

60174

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000151

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.000161

AC XY:

AN XY:

74378

show subpopulations

African (AFR)

AF:

0.0000482

AC:

AN:

41460

American (AMR)

AF:

0.0000654

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5200

South Asian (SAS)

AF:

0.000207

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.000753

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000162

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.488

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000665

Hom.:

Bravo

AF:

0.000159

EpiCase

AF:

0.000109

EpiControl

AF:

0.000356

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Glycogen storage disease, type II

Benign:3

Jan 22, 2020

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:curation

The c.663C>T (p.Ile221=) variant in GAA has not been previously reported in individuals with Glycogen Storage Disease II but has been reported as a VUS by EGL Genetic Diagnostics and a likely benign variant by Invitae in ClinVar (Variation ID: 456426). This variant has been identified in 0.061% (12/19660) of European (Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs142878958). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. Computational splice prediction tools and conservation analyses suggest that this variant may not impact the protein, though this information is not predictive enough to rule out pathogenicity. However, novel synonymous variants supported by computational evidence without raised suspicion for an impact are likely benign (Richards 2015). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely benign. ACMG/AMP Criteria applied: PM2, BP4, BP7 (Richards 2015). -

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 22, 2021

Genome-Nilou Lab

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:2

Apr 27, 2017

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 25, 2019

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis, which includes splice predictors and evolutionary conservation, suggests this variant may impact gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; Has not been previously published as pathogenic or benign to our knowledge -

Cardiovascular phenotype

Benign:1

May 24, 2022

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.64

CADD

Benign

2.4

(source)

DANN

Benign

0.85

PhyloP100

-1.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=100/0

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over