rs370792293

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM2PP3PP5_Very_Strong

The NM_000642.3(AGL):​c.664+3A>G variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00000807 in 1,611,320 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

AGL
NM_000642.3 splice_region, intron

Scores

1
1
Splicing: ADA: 0.9992
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 4.21

Publications

2 publications found
Variant links:
Genes affected
AGL (HGNC:321): (amylo-alpha-1, 6-glucosidase, 4-alpha-glucanotransferase) This gene encodes the glycogen debrancher enzyme which is involved in glycogen degradation. This enzyme has two independent catalytic activities which occur at different sites on the protein: a 4-alpha-glucotransferase activity and a amylo-1,6-glucosidase activity. Mutations in this gene are associated with glycogen storage disease although a wide range of enzymatic and clinical variability occurs which may be due to tissue-specific alternative splicing. Alternatively spliced transcripts encoding different isoforms have been described. [provided by RefSeq, Jul 2008]
AGL Gene-Disease associations (from GenCC):
  • glycogen storage disease III
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Ambry Genetics, Laboratory for Molecular Medicine, Myriad Women’s Health, Orphanet, G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
PP5
Variant 1-99864592-A-G is Pathogenic according to our data. Variant chr1-99864592-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 188994.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
AGLNM_000642.3 linkc.664+3A>G splice_region_variant, intron_variant Intron 5 of 33 ENST00000361915.8 NP_000633.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
AGLENST00000361915.8 linkc.664+3A>G splice_region_variant, intron_variant Intron 5 of 33 1 NM_000642.3 ENSP00000355106.3

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152230
Hom.:
0
Cov.:
33
show subpopulations
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
250976
AF XY:
0.00000737
show subpopulations
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:
0.0000265
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
0.00000754
AC:
11
AN:
1459090
Hom.:
0
Cov.:
31
AF XY:
0.00000551
AC XY:
4
AN XY:
726094
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33424
American (AMR)
AF:
0.00
AC:
0
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26106
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39606
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86138
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53334
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
0.00000901
AC:
10
AN:
1109688
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60324
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.452
Heterozygous variant carriers
0
1
2
4
5
6
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:
152230
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74378
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41466
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000253
Hom.:
0
Bravo
AF:
0.0000189
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Glycogen storage disease type III Pathogenic:7
Sep 30, 2014
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Feb 14, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 01, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 5 of the AGL gene. It does not directly change the encoded amino acid sequence of the AGL protein. RNA analysis indicates that this variant induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs370792293, gnomAD 0.002%). This variant has been observed in individual(s) with glycogen storage disease type III (PMID: 12442284, 16705713, 21691223). This variant is also known as IVS6 +3 A>G. ClinVar contains an entry for this variant (Variation ID: 188994). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 5 (also known as exon 6), but is expected to preserve the integrity of the reading-frame (PMID: 12442284). For these reasons, this variant has been classified as Pathogenic. -

Sep 16, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jul 15, 2021
Genome-Nilou Lab
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 31, 2014
Division of Human Genetics, Children's Hospital of Philadelphia
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Nov 26, 2023
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Glycogen storage disease IIIa Pathogenic:1
Mar 05, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: AGL c.664+3A>G alters a nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Three predict the variant weakens a 5' donor site. At least one publication reports experimental evidence that this variant affects mRNA splicing (Lucchiar_2002). The variant allele was found at a frequency of 1.6e-05 in 250976 control chromosomes (gnomAD). c.664+3A>G has been reported in the literature in multiple individuals affected with Glycogen Storage Disease Type IIIa (Lucchiari_2002, Lucchiari_2006, Minen_2011, Vega_2016). These data indicate that the variant is very likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 26913919, 12442284, 16705713, 21691223). ClinVar contains an entry for this variant (Variation ID: 188994). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.20
CADD
Benign
23
DANN
Uncertain
0.97
PhyloP100
4.2
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.93
SpliceAI score (max)
0.35
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.35
Position offset: -3

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

Publications

Other links and lift over

dbSNP: rs370792293; hg19: chr1-100330148; API