rs113993985

Positions:

• chr14-50910049-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_002863.5(PYGL):​c.2023T>A​(p.Ser675Thr) variant causes a missense 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. Variant has been reported in ClinVar as not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S675L) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PYGL NM_002863.5 missense
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 9.29

Genes affected

PYGL (HGNC:9725): (glycogen phosphorylase L) This gene encodes a homodimeric protein that catalyses the cleavage of alpha-1,4-glucosidic bonds to release glucose-1-phosphate from liver glycogen stores. This protein switches from inactive phosphorylase B to active phosphorylase A by phosphorylation of serine residue 15. Activity of this enzyme is further regulated by multiple allosteric effectors and hormonal controls. Humans have three glycogen phosphorylase genes that encode distinct isozymes that are primarily expressed in liver, brain and muscle, respectively. The liver isozyme serves the glycemic demands of the body in general while the brain and muscle isozymes supply just those tissues. In glycogen storage disease type VI, also known as Hers disease, mutations in liver glycogen phosphorylase inhibit the conversion of glycogen to glucose and results in moderate hypoglycemia, mild ketosis, growth retardation and hepatomegaly. Alternative splicing results in multiple transcript variants encoding different isoforms.[provided by RefSeq, Feb 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr14-50910048-G-A is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PYGL	NM_002863.5	c.2023T>A	p.Ser675Thr	missense_variant	17/20	ENST00000216392.8	NP_002854.3
PYGL	NM_001163940.2	c.1921T>A	p.Ser641Thr	missense_variant	16/19		NP_001157412.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PYGL	ENST00000216392.8	c.2023T>A	p.Ser675Thr	missense_variant	17/20	1	NM_002863.5	ENSP00000216392	P1
PYGL	ENST00000532462.5	c.2023T>A	p.Ser675Thr	missense_variant	17/20	1		ENSP00000431657
PYGL	ENST00000544180.6	c.1921T>A	p.Ser641Thr	missense_variant	16/19	2		ENSP00000443787
PYGL	ENST00000532107.2	n.196T>A		non_coding_transcript_exon_variant	2/4	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: not provided

Submissions summary: Other:1

Revision: no classification provided

Submissions by phenotype

Glycogen storage disease, type VI Other:1

not provided, no classification provided

literature only

GeneReviews

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	.;.;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.34	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	.;.;H
MutationTaster	Benign	1.0	A;A;A
PrimateAI	Pathogenic	0.88	D
PROVEAN	Uncertain	-2.8	D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	.;.;D
Vest4		0.94
MutPred		0.91		Loss of glycosylation at S675 (P = 0.0153);.;Loss of glycosylation at S675 (P = 0.0153);
MVP		0.99
MPC		0.52
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.97
gMVP		0.92

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: rs113993985; hg19: chr14-51376767;