chr1-99851046-G-A

Position:

• chr1-99851046-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.4G>A​(p.Gly2Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/21 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. G2G) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: AGL NM_000642.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.59

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=0.2153984).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AGL	NM_000642.3	c.4G>A	p.Gly2Arg	missense_variant	2/34	ENST00000361915.8	NP_000633.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AGL	ENST00000361915.8	c.4G>A	p.Gly2Arg	missense_variant	2/34	1	NM_000642.3	ENSP00000355106.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251422 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135894

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Glycogen storage disease type III Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 21, 2022

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. 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. ClinVar contains an entry for this variant (Variation ID: 1020831). This variant has not been reported in the literature in individuals affected with AGL-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.0009%). This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 2 of the AGL protein (p.Gly2Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.099	T
BayesDel_noAF	Benign	-0.38
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.044	T;T;T;T
Eigen	Benign	-0.17
Eigen_PC	Benign	-0.047
FATHMM_MKL	Benign	0.52	D
LIST_S2	Benign	0.74	T;.;.;.
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.22	T;T;T;T
MetaSVM	Benign	-0.82	T
MutationAssessor	Benign	1.8	L;L;L;L
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	0.040	N;N;N;N
REVEL	Benign	0.081
Sift	Uncertain	0.026	D;D;D;D
Sift4G	Benign	0.18	T;T;T;T
Polyphen		0.12	B;B;B;B
Vest4		0.28
MutPred		0.33		Gain of MoRF binding (P = 0.009);Gain of MoRF binding (P = 0.009);Gain of MoRF binding (P = 0.009);Gain of MoRF binding (P = 0.009);
MVP		0.76
MPC		0.061
ClinPred		0.34	T
GERP RS		3.4
Varity_R		0.078
gMVP		0.39

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: rs1218915839; hg19: chr1-100316602;