17-80105131-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1PM2PP2BP4_Moderate

The NM_000152.5(GAA):​c.545C>T​(p.Thr182Met) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000231 in 1,604,036 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/24 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T182R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

GAA
NM_000152.5 missense, splice_region

Scores

1
3
14
Splicing: ADA: 0.02217
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 0.683

Publications

6 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_000152.5
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 201 curated pathogenic missense variants (we use a threshold of 10). The gene has 50 curated benign missense variants. Gene score misZ: -0.63308 (below the threshold of 3.09). Trascript score misZ: -0.32889 (below the threshold of 3.09). GenCC associations: The gene is linked to glycogen storage disease due to acid maltase deficiency, infantile onset, glycogen storage disease II, glycogen storage disease due to acid maltase deficiency, late-onset.
BP4
Computational evidence support a benign effect (MetaRNN=0.19151068).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GAANM_000152.5 linkc.545C>T p.Thr182Met missense_variant, splice_region_variant Exon 2 of 20 ENST00000302262.8 NP_000143.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GAAENST00000302262.8 linkc.545C>T p.Thr182Met missense_variant, splice_region_variant Exon 2 of 20 1 NM_000152.5 ENSP00000305692.3

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152238
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000482
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000211
AC:
5
AN:
236756
AF XY:
0.0000230
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000291
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000282
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000227
AC:
33
AN:
1451798
Hom.:
0
Cov.:
36
AF XY:
0.0000194
AC XY:
14
AN XY:
721556
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33402
American (AMR)
AF:
0.0000224
AC:
1
AN:
44666
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26068
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39572
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86198
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47074
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5740
European-Non Finnish (NFE)
AF:
0.0000271
AC:
30
AN:
1108932
Other (OTH)
AF:
0.00
AC:
0
AN:
60146
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000263
AC:
4
AN:
152238
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74376
show subpopulations
African (AFR)
AF:
0.0000482
AC:
2
AN:
41466
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.00
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000167
AC:
2
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Glycogen storage disease, type II Uncertain:3
Jul 14, 2021
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Jul 21, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 182 of the GAA protein (p.Thr182Met). This variant is present in population databases (rs200524747, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with GAA-related conditions. ClinVar contains an entry for this variant (Variation ID: 1199276). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The methionine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Sep 29, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not provided Uncertain:1
Jan 18, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Has not been previously published as pathogenic or benign to our knowledge; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.079
BayesDel_addAF
Benign
-0.084
T
BayesDel_noAF
Benign
-0.26
CADD
Benign
19
DANN
Uncertain
0.99
DEOGEN2
Benign
0.34
T;.;D;D
Eigen
Benign
-0.38
Eigen_PC
Benign
-0.32
FATHMM_MKL
Benign
0.67
D
LIST_S2
Benign
0.80
T;T;.;T
M_CAP
Uncertain
0.27
D
MetaRNN
Benign
0.19
T;T;T;T
MetaSVM
Benign
-0.64
T
MutationAssessor
Benign
0.0
.;.;L;L
PhyloP100
0.68
PrimateAI
Benign
0.27
T
PROVEAN
Benign
0.0
.;.;N;N
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;.;T;T
Sift4G
Uncertain
0.010
D;D;D;D
Vest4
0.0
ClinPred
0.074
T
GERP RS
1.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.29
gMVP
0.55
Mutation Taster
=65/35
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.022
dbscSNV1_RF
Benign
0.076
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

Publications

Other links and lift over

dbSNP: rs200524747; hg19: chr17-78078930; API