chr1-99884645-A-G

Position:

• chr1-99884645-A-G

Variant summary

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

The NM_000642.3(AGL):​c.2623A>G​(p.Lys875Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,690 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K875Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: AGL NM_000642.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 8.38

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AGL	NM_000642.3	c.2623A>G	p.Lys875Glu	missense_variant	20/34	ENST00000361915.8	NP_000633.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AGL	ENST00000361915.8	c.2623A>G	p.Lys875Glu	missense_variant	20/34	1	NM_000642.3	ENSP00000355106.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461690 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727142

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

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: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.00000378

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, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 02, 2021	This sequence change replaces lysine with glutamic acid at codon 875 of the AGL protein (p.Lys875Glu). The lysine residue is weakly conserved and there is a small physicochemical difference between lysine and glutamic acid. 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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. -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Aug 01, 2020	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.095
BayesDel_addAF	Uncertain	0.077	D
BayesDel_noAF	Benign	-0.13
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.039	T;T;T;T;.
Eigen	Uncertain	0.28
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.78	T;.;.;.;T
M_CAP	Benign	0.025	D
MetaRNN	Uncertain	0.66	D;D;D;D;D
MetaSVM	Benign	-0.85	T
MutationAssessor	Uncertain	2.7	M;M;M;M;.
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-0.69	N;N;N;N;N
REVEL	Benign	0.27
Sift	Benign	0.56	T;T;T;T;T
Sift4G	Benign	0.49	T;T;T;T;T
Polyphen		0.70	P;P;P;P;P
Vest4		0.68
MutPred		0.41		Loss of ubiquitination at K875 (P = 0.0077);Loss of ubiquitination at K875 (P = 0.0077);Loss of ubiquitination at K875 (P = 0.0077);Loss of ubiquitination at K875 (P = 0.0077);.;
MVP		0.82
MPC		0.096
ClinPred		0.93	D
GERP RS		5.7
Varity_R		0.32
gMVP		0.60

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: rs750932668; hg19: chr1-100350201;