rs755117847

Positions:

• chr11-64759819-TCA-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_005609.4(PYGM):​c.78_79del​(p.Glu27AlafsTer50) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000558 in 1,614,042 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: PYGM NM_005609.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 5.97

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 262 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-64759819-TCA-T is Pathogenic according to our data. Variant chr11-64759819-TCA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188778.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-64759819-TCA-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PYGM	NM_005609.4	c.78_79del	p.Glu27AlafsTer50	frameshift_variant	1/20	ENST00000164139.4
PYGM	NM_001164716.1	c.78_79del	p.Glu27AlafsTer50	frameshift_variant	1/18

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PYGM	ENST00000164139.4	c.78_79del	p.Glu27AlafsTer50	frameshift_variant	1/20	1	NM_005609.4	P1
PYGM	ENST00000377432.7	c.78_79del	p.Glu27AlafsTer50	frameshift_variant	1/18	2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152160 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

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

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251480 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135918

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461882 Hom.: 0 AF XY: 0.00000550 AC XY: 4 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000719

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152160 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74328

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000151

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Glycogen storage disease, type V Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Apr 20, 2023	- -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	May 13, 2014	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 01, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Sep 19, 2023	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 188778). This variant is also known as T25fs. This premature translational stop signal has been observed in individual(s) with PYGM-related conditions (PMID: 15979037). This variant is present in population databases (rs755117847, gnomAD 0.002%). This sequence change creates a premature translational stop signal (p.Glu27Alafs*50) 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). -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 20, 2024	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jan 07, 2020

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 18067156, 19670320, 15979037, 29926259, 29143597, 21802952, 17404776, 16786513, 32528171) -

Computational scores

Source: dbNSFP v4.3

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: rs755117847; hg19: chr11-64527291;