rs780358808

Positions:

• chr16-30756695-A-C
• chr16-30756695-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000294.3(PHKG2):​c.907A>C​(p.Thr303Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,748 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PHKG2 NM_000294.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.58

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17851236).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PHKG2	NM_000294.3	c.907A>C	p.Thr303Pro	missense_variant	9/10	ENST00000563588.6	NP_000285.1
PHKG2	NM_001172432.2	c.907A>C	p.Thr303Pro	missense_variant	9/11		NP_001165903.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PHKG2	ENST00000563588.6	c.907A>C	p.Thr303Pro	missense_variant	9/10	1	NM_000294.3	ENSP00000455607.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250844 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135708

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: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461748 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727170

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Glycogen storage disease IXc Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 01, 2021

This sequence change replaces threonine with proline at codon 303 of the PHKG2 protein (p.Thr303Pro). The threonine residue is highly conserved and there is a small physicochemical difference between threonine and proline. This variant is present in population databases (rs780358808, ExAC 0.002%). This variant has not been reported in the literature in individuals affected with PHKG2-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt PHKG2 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.090
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.39
CADD	Benign	23
DANN	Uncertain	0.98
DEOGEN2	Benign	0.26	T;.;.
Eigen	Benign	-0.020
Eigen_PC	Benign	0.16
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.60	T;T;T
M_CAP	Benign	0.0070	T
MetaRNN	Benign	0.18	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.55	N;N;.
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-1.1	N;N;N
REVEL	Benign	0.11
Sift	Benign	0.075	T;T;T
Sift4G	Benign	0.28	T;T;T
Polyphen		0.045	B;B;.
Vest4		0.28
MutPred		0.55		Loss of MoRF binding (P = 0.0547);Loss of MoRF binding (P = 0.0547);.;
MVP		0.56
MPC		0.51
ClinPred		0.19	T
GERP RS		3.6
Varity_R		0.11
gMVP		0.55

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: rs780358808; hg19: chr16-30768016;