rs137853592

Variant names:

• chr16-30756396-T-G
• rs137853592
• NM_000294.3:c.677T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_000294.3(PHKG2):​c.677T>G​(p.Leu226Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000889 in 1,461,822 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 (no stars). Synonymous variant affecting the same amino acid position (i.e. L226L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: PHKG2 NM_000294.3 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.93
• Publications: 3 publications found

Genes affected

PHKG2 (HGNC:8931): (phosphorylase kinase catalytic subunit gamma 2) Phosphorylase kinase is a polymer of 16 subunits, four each of alpha, beta, gamma and delta. The alpha subunit includes the skeletal muscle and hepatic isoforms, encoded by two different genes. The beta subunit is the same in both the muscle and hepatic isoforms, and encoded by one gene. The gamma subunit also includes the skeletal muscle and hepatic isoforms, and the hepatic isoform is encoded by this gene. The delta subunit is a calmodulin and can be encoded by three different genes. The gamma subunits contain the active site of the enzyme, whereas the alpha and beta subunits have regulatory functions controlled by phosphorylation. The delta subunit mediates the dependence of the enzyme on calcium concentration. Mutations in this gene cause glycogen storage disease type 9C, also known as autosomal liver glycogenosis. Alternatively spliced transcript variants encoding different isoforms have been identified in this gene.[provided by RefSeq, Feb 2010]

PHKG2 Gene-Disease associations (from GenCC):

• glycogen storage disease IXc

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• glycogen storage disease due to liver phosphorylase kinase deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• PP5: Variant 16-30756396-T-G is Pathogenic according to our data. Variant chr16-30756396-T-G is described in ClinVar as Pathogenic. ClinVar VariationId is 13631.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PHKG2	NM_000294.3	c.677T>G	p.Leu226Arg	missense_variant	Exon 8 of 10	ENST00000563588.6	NP_000285.1
PHKG2	NM_001172432.2	c.677T>G	p.Leu226Arg	missense_variant	Exon 8 of 11		NP_001165903.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PHKG2	ENST00000563588.6	c.677T>G	p.Leu226Arg	missense_variant	Exon 8 of 10	1	NM_000294.3	ENSP00000455607.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000889 AC: 13 AN: 1461822 Hom.: 0 Cov.: 34 AF XY: 0.00000825 AC XY: 6 AN XY: 727210

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53352

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000117 AC: 13 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Glycogen storage disease IXc Pathogenic:1

May 01, 2000

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.56	D;T;.;.;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.97	D;D;D;D;D
M_CAP	Uncertain	0.19	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D
MetaSVM	Uncertain	0.18	D
MutationAssessor	Pathogenic	3.5	H;.;H;.;.
PhyloP100		7.9
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-5.3	D;D;D;D;D
REVEL	Pathogenic	0.70
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	D;.;D;.;.
Vest4		0.98
MutPred		0.97		Loss of stability (P = 0.0075);Loss of stability (P = 0.0075);Loss of stability (P = 0.0075);.;Loss of stability (P = 0.0075);
MVP		0.92
MPC		1.4
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.99
gMVP		0.98
Mutation Taster		=4/96	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs137853592; hg19: chr16-30767717;