dbSNP rs201201443: AGL:c.2681+1G>A (chr1-99884704-G-A) – ACMG Classification: Pathogenic (16 pts)

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1_ModeratePS3PM2PP5_Very_Strong

The NM_000642.3(AGL):c.2681+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,613,706 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 (★★). ClinVar reports functional evidence for this variant: "SCV001338430: The variant allele was found at a frequency of 3.2e-05 in 251020 control chromosomes (gnomAD). c.2681+1G>A has been reported in the literature in multiple individuals affected with Glycogen Storage Disease Type III (Hadjigeorgiou_1999, Lucchiari_2007). These data indicate that the variant is very likely to be associated with disease. AGL activity and protein were found to be almost absent in patients muscle specimens (Hadjigeorgiou_1999).; SCV004105908: Functional studies have shown that the c.2681+1G>A variant leads to abnormal splicing (Hadjigeorgiou et al. 1999. PubMed ID: 10472540; Abdullah et al. 2019. PubMed ID: 31028654).".

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

AGL
NM_000642.3 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 8.56

Publications

5 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: Ambry Genetics, ClinGen, Orphanet, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Laboratory for Molecular Medicine, Myriad Women’s Health

AGL links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.029354207 fraction of the gene. Cryptic splice site detected, with MaxEntScore 8.1, offset of 41, new splice context is: taaGTaagt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PS3

PS3 evidence extracted from ClinVar submissions: SCV001338430: The variant allele was found at a frequency of 3.2e-05 in 251020 control chromosomes (gnomAD). c.2681+1G>A has been reported in the literature in multiple individuals affected with Glycogen Storage Disease Type III (Hadjigeorgiou_1999, Lucchiari_2007). These data indicate that the variant is very likely to be associated with disease. AGL activity and protein were found to be almost absent in patients muscle specimens (Hadjigeorgiou_1999).; SCV004105908: Functional studies have shown that the c.2681+1G>A variant leads to abnormal splicing (Hadjigeorgiou et al. 1999. PubMed ID: 10472540; Abdullah et al. 2019. PubMed ID: 31028654).

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 1-99884704-G-A is Pathogenic according to our data. Variant chr1-99884704-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 281229.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000642.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein	UniProt
AGL	NM_000642.3	MANE Select	c.2681+1G>A	splice_donor intron	N/A	NP_000633.2	P35573-1
AGL	NM_000028.3		c.2681+1G>A	splice_donor intron	N/A	NP_000019.2	P35573-1
AGL	NM_000643.3		c.2681+1G>A	splice_donor intron	N/A	NP_000634.2	A0A0S2A4E4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein	UniProt
AGL	ENST00000361915.8	TSL:1 MANE Select	c.2681+1G>A	splice_donor intron	N/A	ENSP00000355106.3	P35573-1
AGL	ENST00000294724.8	TSL:1	c.2681+1G>A	splice_donor intron	N/A	ENSP00000294724.4	P35573-1
AGL	ENST00000370163.7	TSL:1	c.2681+1G>A	splice_donor intron	N/A	ENSP00000359182.3	P35573-1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152112

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000319

AC:

AN:

250950

AF XY:

0.0000442

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000353

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1461476

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

727036

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33460

American (AMR)

AF:

0.00

AC:

AN:

44684

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26122

East Asian (EAS)

AF:

0.0000756

AC:

AN:

39668

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53328

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000144

AC:

AN:

1111816

Other (OTH)

AF:

0.00

AC:

AN:

60380

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.509

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:

0.0000197

AC:

AN:

152230

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74410

show subpopulations

African (AFR)

AF:

0.0000482

AC:

AN:

41534

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10586

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68020

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.408

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:

0.00

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

ClinVar submissions

Significance:Pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Glycogen storage disease type III (7)

AGL-related disorder (1)

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.47

BayesDel_noAF

Pathogenic

0.25

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.93

FATHMM_MKL

Pathogenic

0.99

PhyloP100

8.6

GERP RS

4.7

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

0.93

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.46

Position offset: 40

DS_DL_spliceai

0.98

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over