1-99912471-CA-CAA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000642.3(AGL):​c.3911dupA​(p.Asn1304fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000174 in 1,611,946 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

AGL
NM_000642.3 frameshift

Scores

Not classified

Clinical Significance

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

Conservation

PhyloP100: 0.125
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-99912471-C-CA is Pathogenic according to our data. Variant chr1-99912471-C-CA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 370832.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
AGLNM_000642.3 linkuse as main transcriptc.3911dupA p.Asn1304fs frameshift_variant 29/34 ENST00000361915.8 NP_000633.2 P35573-1A0A0S2A4E4

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
AGLENST00000361915.8 linkuse as main transcriptc.3911dupA p.Asn1304fs frameshift_variant 29/341 NM_000642.3 ENSP00000355106.3 P35573-1

Frequencies

GnomAD3 genomes
AF:
0.0000330
AC:
5
AN:
151530
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000577
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:
0.000482
GnomAD3 exomes
AF:
0.0000401
AC:
10
AN:
249526
Hom.:
0
AF XY:
0.0000667
AC XY:
9
AN XY:
134920
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000399
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000330
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000442
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000157
AC:
23
AN:
1460416
Hom.:
0
Cov.:
30
AF XY:
0.0000220
AC XY:
16
AN XY:
726552
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.000306
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.0000188
Gnomad4 NFE exome
AF:
0.00000810
Gnomad4 OTH exome
AF:
0.0000497
GnomAD4 genome
AF:
0.0000330
AC:
5
AN:
151530
Hom.:
0
Cov.:
33
AF XY:
0.0000541
AC XY:
4
AN XY:
73978
show subpopulations
Gnomad4 AFR
AF:
0.0000242
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.000577
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.000482
Bravo
AF:
0.0000264

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:8
Pathogenic, no assertion criteria providedclinical testingNatera, Inc.Sep 16, 2020- -
Pathogenic, criteria provided, single submitterclinical testingGenome-Nilou LabJul 15, 2021- -
Likely pathogenic, no assertion criteria providedclinical testingCounsylApr 21, 2016- -
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsOct 18, 2021- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 13, 2023This sequence change creates a premature translational stop signal (p.Asn1304Lysfs*7) in the AGL gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in AGL are known to be pathogenic (PMID: 19299494). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This premature translational stop signal has been observed in individuals with glycogen storage disease type III (PMID: 9584265, 23430832; Invitae). It has also been observed to segregate with disease in related individuals. This variant is also known as c.3904insA. ClinVar contains an entry for this variant (Variation ID: 370832). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingBaylor GeneticsMar 27, 2024- -
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpSep 21, 2020Variant summary: AGL c.3911dupA (p.Asn1304LysfsX7) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 4e-05 in 249526 control chromosomes (gnomAD). This frequency is not higher than expected for a pathogenic variant in AGL causing Glycogen Storage Disease Type III (4e-05 vs 0.0023), allowing no conclusion about variant significance. c.3911dupA (also known as c.3904insA) has been reported in the literature, in the compound heterozygous and homozygous state, in multiple individuals affected with Glycogen Storage Disease Type III (e.g. Parvari_1997, Lee_2011). These data indicate that the variant is very likely to be associated with disease. Experimental evidence demonstrated very low enzymatic activity and glycogen accumulation in the liver, in homozygous patients (Lee_2011, Ponzi_2019). Two ClinVar submitters (evaluation after 2014) cite the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Likely pathogenic, criteria provided, single submitterclinical testingCentre for Human GeneticsAug 27, 2020disease causing -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs745757264; hg19: chr1-100378027; API