1-99900857-C-T

Position:

• chr1-99900857-C-T

Variant summary

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

The NM_000642.3(AGL):​c.3584C>T​(p.Thr1195Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000696 in 1,437,706 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. 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. T1195R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: AGL NM_000642.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.352

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=0.14658314).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AGL	NM_000642.3	c.3584C>T	p.Thr1195Ile	missense_variant	26/34	ENST00000361915.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AGL	ENST00000361915.8	c.3584C>T	p.Thr1195Ile	missense_variant	26/34	1	NM_000642.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.96e-7 AC: 1 AN: 1437706 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 716592

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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

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

Sep 01, 2021

This sequence change replaces threonine with isoleucine at codon 1195 of the AGL protein (p.Thr1195Ile). The threonine residue is weakly conserved and there is a moderate physicochemical difference between threonine and isoleucine. 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 output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The isoleucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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	0.078
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.39
CADD	Benign	15
DANN	Benign	0.97
DEOGEN2	Benign	0.065	T;T;T;T;.
Eigen	Benign	-0.51
Eigen_PC	Benign	-0.37
FATHMM_MKL	Benign	0.65	D
LIST_S2	Benign	0.76	T;.;.;.;T
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.15	T;T;T;T;T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	1.7	L;L;L;L;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-1.6	N;N;N;N;N
REVEL	Benign	0.090
Sift	Benign	0.17	T;T;T;T;T
Sift4G	Benign	0.18	T;T;T;T;T
Polyphen		0.0	B;B;B;B;B
Vest4		0.17
MutPred		0.41		Loss of phosphorylation at T1195 (P = 0.0437);Loss of phosphorylation at T1195 (P = 0.0437);Loss of phosphorylation at T1195 (P = 0.0437);Loss of phosphorylation at T1195 (P = 0.0437);.;
MVP		0.75
MPC		0.044
ClinPred		0.11	T
GERP RS		3.7
Varity_R		0.047
gMVP		0.56

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: rs148930543; hg19: chr1-100366413;