11-64750557-G-T

Variant names:

• chr11-64750557-G-T
• rs119103256
• NM_005609.4:c.1996C>A

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_005609.4(PYGM):​c.1996C>A​(p.Gln666Lys) 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q666E) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PYGM NM_005609.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.96
• Publications: 0 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain in NM_005609.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-64750557-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2303.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 37 curated pathogenic missense variants (we use a threshold of 10). The gene has 5 curated benign missense variants. Gene score misZ: 0.046884 (below the threshold of 3.09). Trascript score misZ: 1.6804 (below the threshold of 3.09). GenCC associations: The gene is linked to glycogen storage disease V.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.962

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005609.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PYGM	NM_005609.4	MANE Select	c.1996C>A	p.Gln666Lys	missense	Exon 17 of 20	NP_005600.1
	PYGM	NM_001164716.1		c.1732C>A	p.Gln578Lys	missense	Exon 15 of 18	NP_001158188.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PYGM	ENST00000164139.4	TSL:1 MANE Select	c.1996C>A	p.Gln666Lys	missense	Exon 17 of 20	ENSP00000164139.3
	PYGM	ENST00000377432.7	TSL:2	c.1732C>A	p.Gln578Lys	missense	Exon 15 of 18	ENSP00000366650.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	H
PhyloP100		10
PrimateAI	Pathogenic	0.88	D
PROVEAN	Uncertain	-3.5	D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.90		Gain of ubiquitination at Q666 (P = 0.0104)
MVP		0.96
MPC		0.95
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.98
gMVP		0.93
Mutation Taster		=10/90	disease causing

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

Other links and lift over

dbSNP: rs119103256; hg19: chr11-64518029;