rs114073621

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_005609.4(PYGM):c.1948C>T(p.Arg650*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 1,614,032 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

PYGM
NM_005609.4 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 0.454

Publications

7 publications found

Variant links:

Genes affected

PYGM (HGNC:9726): (glycogen phosphorylase, muscle associated) This gene encodes a muscle enzyme involved in glycogenolysis. Highly similar enzymes encoded by different genes are found in liver and brain. Mutations in this gene are associated with McArdle disease (myophosphorylase deficiency), a glycogen storage disease of muscle. Alternative splicing results in multiple transcript variants.[provided by RefSeq, Sep 2009]

PYGM Gene-Disease associations (from GenCC):

glycogen storage disease V
Inheritance: AR, AD Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics, Genomics England PanelApp

PYGM links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PP5

Variant 11-64751346-G-A is Pathogenic according to our data. Variant chr11-64751346-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 433147.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PYGM	NM_005609.4 link	c.1948C>T	p.Arg650*	stop_gained	Exon 16 of 20	ENST00000164139.4	NP_005600.1	P11217-1
PYGM	NM_001164716.1 link	c.1684C>T	p.Arg562*	stop_gained	Exon 14 of 18		NP_001158188.1	P11217-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
PYGM	ENST00000164139.4 link	c.1948C>T	p.Arg650*	stop_gained	Exon 16 of 20	1	NM_005609.4	ENSP00000164139.3	P11217-1
PYGM	ENST00000377432.7 link	c.1684C>T	p.Arg562*	stop_gained	Exon 14 of 18	2		ENSP00000366650.3	P11217-2
PYGM	ENST00000462303.1 link	n.272C>T		non_coding_transcript_exon_variant	Exon 3 of 3	2

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152204

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251386

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000130

AC:

AN:

1461828

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727212

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53364

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000153

AC:

AN:

1112010

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.499

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74358

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41430

American (AMR)

AF:

0.00

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.000288

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5202

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68038

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.558

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Glycogen storage disease, type V

Pathogenic:7

Jun 13, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: PYGM c.1948C>T (p.Arg650X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 4e-06 in 251386 control chromosomes (gnomAD). c.1948C>T has been observed in individual(s) affected with Glycogen Storage Disease, Type V (McArdle disease) (e.g. Aquaron_2007). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 17324573). ClinVar contains an entry for this variant (Variation ID: 433147). Based on the evidence outlined above, the variant was classified as pathogenic. -

Sep 16, 2020

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jan 12, 2016

Molecular Diagnostics Lab, Nemours Children's Health, Delaware

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 25, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 433147). This premature translational stop signal has been observed in individuals with glycogen storage disease type V (PMID: 17324573; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Arg650*) in the PYGM gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PYGM are known to be pathogenic (PMID: 8316268, 16786513). -

May 20, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Neuberg Centre For Genomic Medicine, NCGM

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The stop gained p.R650* in PYGM (NM_005609.4) has been previously reported in affected individuals (Aquaron R et al,Bruno C et al). It has been submitted to ClinVar as Pathogenic. The p.R650* variant is observed in 1/18,392 (0.0054%) alleles from individuals of East Asian background in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. This variant is predicted to cause loss of normal protein function through protein truncation. Loss of function mutations have been previously reported to be disease causing. For these reasons, this variant has been classified as Pathogenic. -

Mar 27, 2024

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

See cases

Pathogenic:1

Jul 28, 2023

Gene Friend Way, National Innovation Center

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg650*) in the PYGM gene. It is expected to result in an absent or disrupted protein product. This premature translational stop signal has been observed in individuals with glycogen storage disease type V (PMID: 17324573). Recent genetic and functional studies have identified a role of abnormal glycinergic signaling in Autism Spectrum Disorder (ASD) (PMID: 28270747). In our study, a child diagnosed with ASD is the carrier of this mutation and also PRNP (rs1799990). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.58

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Uncertain

0.63

Eigen_PC

Uncertain

0.48

FATHMM_MKL

Uncertain

0.90

PhyloP100

0.45

Vest4

0.94

GERP RS

4.2

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over