1-99851053-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000642.3(AGL):c.11G>A(p.Ser4Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00000806 in 1,613,812 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. S4S) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000021 (1 hom.)
• Consequence: AGL NM_000642.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 4.31

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10734919).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AGL	NM_000642.3	c.11G>A	p.Ser4Asn	missense_variant	2/34	ENST00000361915.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AGL	ENST00000361915.8	c.11G>A	p.Ser4Asn	missense_variant	2/34	1	NM_000642.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000657 AC: 10 AN: 152212 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000523

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: 0.000478

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251438 Hom.: 1 AF XY: 0.00 AC XY: 0 AN XY: 135896

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461600 Hom.: 1 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727126

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

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: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000657 AC: 10 AN: 152212 Hom.: 0 Cov.: 33 AF XY: 0.0000807 AC XY: 6 AN XY: 74354

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.000523

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000478

Alfa AF: 0.0000282 Hom.: 0

Bravo AF: 0.000136

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Glycogen storage disease type III Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 27, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Aug 24, 2021	This sequence change replaces serine with asparagine at codon 4 of the AGL protein (p.Ser4Asn). The serine residue is weakly conserved and there is a small physicochemical difference between serine and asparagine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with AGL-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
BayesDel_addAF	Benign	-0.27	T
BayesDel_noAF	Benign	-0.44
Cadd	Benign	20
Dann	Uncertain	0.98
DEOGEN2	Benign	0.037	T;T;T;T
Eigen	Benign	0.0099
Eigen_PC	Benign	0.19
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.64	T;.;.;.
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.11	T;T;T;T
MetaSVM	Benign	-0.81	T
MutationAssessor	Benign	0.97	L;L;L;L
MutationTaster	Benign	0.99	D;D;D;D;D
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-0.040	N;N;N;N
REVEL	Benign	0.13
Sift	Benign	0.50	T;T;T;T
Sift4G	Benign	0.50	T;T;T;T
Polyphen		0.0020	B;B;B;B
Vest4		0.20
MutPred		0.22		Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);
MVP		0.75
MPC		0.039
ClinPred		0.50	T
GERP RS		5.3
Varity_R		0.13
gMVP		0.29

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

Other links and lift over

dbSNP: rs1257997077; hg19: chr1-100316609;