rs61811105

Positions:

• chr1-99864590-G-A
• chr1-99864590-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_000642.3(AGL):​c.664+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: AGL NM_000642.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: 9.68

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 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.04414003 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-99864590-G-A is Pathogenic according to our data. Variant chr1-99864590-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 550254.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1, Likely_pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AGL	NM_000642.3	c.664+1G>A		splice_donor_variant, intron_variant		ENST00000361915.8	NP_000633.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AGL	ENST00000361915.8	c.664+1G>A		splice_donor_variant, intron_variant		1	NM_000642.3	ENSP00000355106.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Glycogen storage disease type III Pathogenic:3 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jan 19, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Apr 11, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jan 05, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	Mar 29, 2024	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.36		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.36		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs61811105; hg19: chr1-100330146;