rs786204481

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000642.3(AGL):c.2309-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,610,292 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

AGL
NM_000642.3 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 9.26

Publications

3 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

AGL links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.9, offset of 1, new splice context is: tgtttttatgtattcctaAGcaa. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 1-99884119-G-A is Pathogenic according to our data. Variant chr1-99884119-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 188804.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
AGL	NM_000642.3 link	c.2309-1G>A		splice_acceptor_variant, intron_variant	Intron 17 of 33	ENST00000361915.8	NP_000633.2	P35573-1A0A0S2A4E4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AGL	ENST00000361915.8 link	c.2309-1G>A		splice_acceptor_variant, intron_variant	Intron 17 of 33	1	NM_000642.3	ENSP00000355106.3		P35573-1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152050

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00000800

AC:

AN:

250122

AF XY:

0.00

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:

0.0000177

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000192

AC:

AN:

1458242

Hom.:

Cov.:

AF XY:

0.0000248

AC XY:

AN XY:

725492

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33378

American (AMR)

AF:

0.00

AC:

AN:

44626

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26080

East Asian (EAS)

AF:

0.00

AC:

AN:

39520

South Asian (SAS)

AF:

0.00

AC:

AN:

85972

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53384

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5650

European-Non Finnish (NFE)

AF:

0.0000252

AC:

AN:

1109398

Other (OTH)

AF:

0.00

AC:

AN:

60234

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.414

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:

0.00000658

AC:

AN:

152050

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74250

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41414

American (AMR)

AF:

0.00

AC:

AN:

15252

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5200

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10590

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67988

Other (OTH)

AF:

0.00

AC:

AN:

2082

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

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:

0.0000180

Hom.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Glycogen storage disease type III

Pathogenic:4

Jul 15, 2021

Genome-Nilou Lab

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 27, 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. -

Dec 10, 2022

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Feb 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects an acceptor splice site in intron 17 of the AGL gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in AGL are known to be pathogenic (PMID: 19299494). This variant is present in population databases (rs786204481, gnomAD 0.002%). Disruption of this splice site has been observed in individuals with glycogen storage disease III (PMID: 20648714, 27460348, 34820282). ClinVar contains an entry for this variant (Variation ID: 188804). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Glycogen storage disease IIIa

Pathogenic:1

Aug 13, 2017

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: The c.2309-1G>A (aka IVS17-1G>A) in a AGL gene is a splice-site variant that alters a highly conserved nucleotide. 5/5 in silico tools via Alamut predict this variant to disrupt a canonical acceptor sequence, however these predictions have yet to be confirmed by functional assay. The variant is absent from control dataset of ExAC (~120120 chrs tested), but is present at a low frequency in gnomAD dataset (2/245384 chrs tested). The observed frequency does not exceed the maximum expected allele frequency for a pathogenic variant of 0.00228. The variant has been reported in affected individuals with enzymatically confirmed dx of GSDIII via publications and is cited as Likely Pathogenic by a reputable database/clinical laboratory. Taken together, the variant was classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.61

BayesDel_noAF

Pathogenic

0.39

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.3

Eigen_PC

Pathogenic

1.1

FATHMM_MKL

Pathogenic

0.99

PhyloP100

9.3

GERP RS

5.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

1.0

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.98

Position offset: 2

DS_AL_spliceai

1.0

Position offset: 1

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