rs771069887

Positions:

• chr1-99892561-TGA-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000642.3(AGL):​c.3216_3217delGA​(p.Glu1072fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,644 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: AGL NM_000642.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:10
• Conservation: PhyloP100: 3.28

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 (HGNC:):

ACMG classification

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 1-99892561-TGA-T is Pathogenic according to our data. Variant chr1-99892561-TGA-T is described in ClinVar as [Pathogenic]. Clinvar id is 432008.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
AGL	NM_000642.3	c.3216_3217delGA	p.Glu1072fs	frameshift_variant	24/34	ENST00000361915.8	NP_000633.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AGL	ENST00000361915.8	c.3216_3217delGA	p.Glu1072fs	frameshift_variant	24/34	1	NM_000642.3	ENSP00000355106.3

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152152 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

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

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251206 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135782

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461374 Hom.: 0 AF XY: 0.00000413 AC XY: 3 AN XY: 726994

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000157

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000328 AC: 5 AN: 152270 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74456

Gnomad4 AFR AF: 0.0000240

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000227

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Glycogen storage disease type III Pathogenic:7

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jan 22, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Feb 08, 2022	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Jul 15, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 28, 2024	This sequence change creates a premature translational stop signal (p.Glu1072Aspfs*36) 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). This variant is present in population databases (rs771069887, gnomAD 0.009%). This premature translational stop signal has been observed in individuals with glycogen storage disease type III (PMID: 20648714, 22035446, 28888851). ClinVar contains an entry for this variant (Variation ID: 432008). For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, no assertion criteria provided	clinical testing	Counsyl	Jul 11, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	DASA	Jan 05, 2022	The c.3216_3217del;p.(Glu1072Aspfs*36) is a null frameshift variant (NMD) in the AGL gene and predicts alteration of the nonsense-mediate decay - NMD is present in a relevantexon to the transcript -PVS1. This sequence change has been observed in affected individual(s) and ClinVar contains an entry for this variant (ClinVar ID: 432008; PMID: 20648714; 22035446; 28888851) - PS4. The variant is present at low allele frequencies population databases (rs771069887– gnomAD 0.003286%; ABraOM no frequency - http://abraom.ib.usp.br/) - PM2_supporting. The p.(Glu1072Aspfs*36) was detected in trans with a pathogenic variant (PMID: 28888851) - PM3. In summary, the currently available evidence indicates that the variant is pathogenic. -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 28, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 13, 2022	Not observed at a significant frequency in large population cohorts (gnomAD); Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 27460348, 19754354, 20648714, 26885414, 23649758, 29809327, 22035446, 23507172, 25602008, 28888851, 31589614) -

Glycogen storage disease IIIa Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Dec 30, 2016

Variant summary: The AGL c.3216_3217delGA (p.Glu1072Aspfs) variant results in a premature termination codon, predicted to cause a truncated or absent AGL protein due to nonsense mediated decay, which are commonly known mechanisms for disease. This variant was found in 1/121086 control chromosomes at a frequency of 0.0000083, which does not exceed the estimated maximal expected allele frequency of a pathogenic AGL variant (0.0022822). The variant was reported in numerous affected individuals and was shown to result in no AGL activity in peripheral leukocytes. Taken together, this variant is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

Other links and lift over

dbSNP: rs771069887; hg19: chr1-100358117;