rs756024023

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PP3PM2_SupportingPM3

This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.546+5G>A variant is in intron 2 of GAA. This variant has been detected in one patient with Pompe disease reported to have deficient GAA activity, but results and clinical information were not provided. This variant has also been reported in one individual with a positive newborn screen for Pompe disease and confirmed deficient GAA enzyme in DBS; while this technically meets criteria for PP4_moderate, we cannot apply this evidence code as there has not been a confirmed phenotype in this individual. This individual was compound heterozygous for this variant and the common c.-32-13T>G variant confirmed in trans (PM3). The highest population minor allele frequency in gnomAD v4.0 is 0.00006714 (5/74860 alleles) in the African/African-American subpopulation, which is lower than the ClinGen Lysosomal Disorders VCEP's threshold for PM2_Supporting (<0.001), meeting this criterion (PM2_Supporting). The computational splicing predictor SpliceAI gives a score of 0.57 for donor loss, predicting that the variant disrupts the donor splice site of intron 2 of GAA (PP3). There is another variant at the same location with a different amino acid change (NM_000152.5:c.546+5G>T) classified as a variant of uncertain significance by the ClinGen Lysosomal Disorders VCEP. There is a ClinVar entry for this variant (Variation ID: 2151633, 2 star review status) with two submitters classifying the variant as a uncertain significance. In summary, this variant has been classified as a VUS for Pompe disease by the ClinGen Lysosomal Disorders VCEP. GAA-Specific ACMG-AMP criteria applied, as specified by the ClinGen LSD VCEP (Specifications Version 2.0): PM3, PM2_Supporting, PP3.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 5, 2023). LINK:https://erepo.genome.network/evrepo/ui/classification/CA8814900/MONDO:0009290/010

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

GAA
NM_000152.5 splice_region, intron

Scores

2
Splicing: ADA: 1.000
2

Clinical Significance

Uncertain significance reviewed by expert panel U:3

Conservation

PhyloP100: 7.26

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 4 ACMG points.

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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GAANM_000152.5 linkc.546+5G>A splice_region_variant, intron_variant Intron 2 of 19 ENST00000302262.8 NP_000143.2 P10253

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GAAENST00000302262.8 linkc.546+5G>A splice_region_variant, intron_variant Intron 2 of 19 1 NM_000152.5 ENSP00000305692.3 P10253

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152246
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000850
AC:
2
AN:
235344
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.000136
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000414
AC:
6
AN:
1450136
Hom.:
0
Cov.:
36
AF XY:
0.00000278
AC XY:
2
AN XY:
720654
show subpopulations
African (AFR)
AF:
0.0000898
AC:
3
AN:
33396
American (AMR)
AF:
0.00
AC:
0
AN:
44652
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26044
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39554
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86186
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
45996
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5716
European-Non Finnish (NFE)
AF:
0.00000271
AC:
3
AN:
1108494
Other (OTH)
AF:
0.00
AC:
0
AN:
60098
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000131
AC:
2
AN:
152246
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74384
show subpopulations
African (AFR)
AF:
0.0000482
AC:
2
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000585
Hom.:
0
Bravo
AF:
0.0000227

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Glycogen storage disease, type II Uncertain:2
Dec 05, 2023
ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel
Significance:Uncertain significance
Review Status:reviewed by expert panel
Collection Method:curation

The NM_000152.5:c.546+5G>A variant is in intron 2 of GAA. This variant has been detected in one patient with Pompe disease reported to have deficient GAA activity, but results and clinical information were not provided. This variant has also been reported in one individual with a positive newborn screen for Pompe disease and confirmed deficient GAA enzyme in DBS; while this technically meets criteria for PP4_moderate, we cannot apply this evidence code as there has not been a confirmed phenotype in this individual. This individual was compound heterozygous for this variant and the common c.-32-13T>G variant confirmed in trans (PM3). The highest population minor allele frequency in gnomAD v4.0 is 0.00006714 (5/74860 alleles) in the African/African-American subpopulation, which is lower than the ClinGen Lysosomal Disorders VCEP's threshold for PM2_Supporting (<0.001), meeting this criterion (PM2_Supporting). The computational splicing predictor SpliceAI gives a score of 0.57 for donor loss, predicting that the variant disrupts the donor splice site of intron 2 of GAA (PP3). There is another variant at the same location with a different amino acid change (NM_000152.5:c.546+5G>T) classified as a variant of uncertain significance by the ClinGen Lysosomal Disorders VCEP. There is a ClinVar entry for this variant (Variation ID: 2151633, 2 star review status) with two submitters classifying the variant as a uncertain significance. In summary, this variant has been classified as a VUS for Pompe disease by the ClinGen Lysosomal Disorders VCEP. GAA-Specific ACMG-AMP criteria applied, as specified by the ClinGen LSD VCEP (Specifications Version 2.0): PM3, PM2_Supporting, PP3. (Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 5, 2023). -

Jul 19, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 2 of the GAA gene. It does not directly change the encoded amino acid sequence of the GAA protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs756024023, gnomAD 0.01%). 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: 2151633). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts the c.546+5G nucleotide in the GAA gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 21232767, 31301153; Invitae). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. 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. -

not provided Uncertain:1
Apr 13, 2023
Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PM2, PM3_Supporting, PP3 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.35
CADD
Benign
22
DANN
Benign
0.96
PhyloP100
7.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.99
SpliceAI score (max)
0.57
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.29
Position offset: 35
DS_DL_spliceai
0.57
Position offset: -5

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

Publications

Other links and lift over

dbSNP: rs756024023; hg19: chr17-78078936; API