rs778051353

Positions:

chrX-18924519-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 4P and 5B. PP3_StrongBP6BS2

The NM_000292.3(PHKA2):c.1576G>A(p.Asp526Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000147 in 1,208,938 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 57 hemizygotes in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000045 ( 0 hom., 2 hem., cov: 23)

Exomes 𝑓: 0.00016 ( 0 hom. 55 hem. )

Consequence

PHKA2
NM_000292.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1

Conservation

PhyloP100: 7.79

Variant links:

Genes affected

PHKA2 (HGNC:8926): (phosphorylase kinase regulatory subunit alpha 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, and the hepatic isoform is encoded by this gene. 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, which are encoded by two different genes. 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 9A, also known as X-linked liver glycogenosis. Alternatively spliced transcript variants have been reported, but the full-length nature of these variants has not been determined.[provided by RefSeq, Feb 2010]

PHKA2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.956

BP6

Variant X-18924519-C-T is Benign according to our data. Variant chrX-18924519-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 566810.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

BS2

High Hemizygotes in GnomAd4 at 2 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PHKA2	NM_000292.3 linkuse as main transcript	c.1576G>A	p.Asp526Asn	missense_variant	16/33	ENST00000379942.5	NP_000283.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PHKA2	ENST00000379942.5 linkuse as main transcript	c.1576G>A	p.Asp526Asn	missense_variant	16/33	1	NM_000292.3	ENSP00000369274	P1
PHKA2	ENST00000464455.1 linkuse as main transcript	n.145G>A		non_coding_transcript_exon_variant	3/3	3

Frequencies

GnomAD3 genomes

AF:

0.0000448

AC:

AN:

111541

Hom.:

Cov.:

AF XY:

0.0000594

AC XY:

AN XY:

33689

show subpopulations

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:

0.0000942

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000382

AC:

AN:

183079

Hom.:

AF XY:

0.0000296

AC XY:

AN XY:

67543

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000857

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000158

AC:

173

AN:

1097397

Hom.:

Cov.:

AF XY:

0.000152

AC XY:

AN XY:

362771

show subpopulations

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:

0.000202

Gnomad4 OTH exome

AF:

0.0000651

GnomAD4 genome

AF:

0.0000448

AC:

AN:

111541

Hom.:

Cov.:

AF XY:

0.0000594

AC XY:

AN XY:

33689

show subpopulations

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:

0.0000942

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000378

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.00

AC:

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Glycogen storage disease IXa1

Uncertain:3

Uncertain significance, no assertion criteria provided	clinical testing	Clinical Genetics Laboratory, University Hospital Schleswig-Holstein	Jun 18, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 07, 2023	This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 526 of the PHKA2 protein (p.Asp526Asn). This variant is present in population databases (rs778051353, gnomAD 0.009%). This missense change has been observed in individual(s) with clinical features of glycogen storage disease type IXa and/or ketotic hypoglycemia symptoms (PMID: 34117828; Invitae). ClinVar contains an entry for this variant (Variation ID: 566810). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on PHKA2 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Aug 05, 2021	- -

PHKA2-related disorder

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jun 04, 2024

The PHKA2 c.1576G>A variant is predicted to result in the amino acid substitution p.Asp526Asn. This variant has been reported in an individual with ketotic hypoglycemia; however, a similarly affected family member did not carry the variant (Benner et al 2021. PubMed ID: 34117828). This variant is reported in 0.0087% of alleles in individuals of European (Non-Finnish) descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 01, 2021

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.71

BayesDel_addAF

Uncertain

0.025

BayesDel_noAF

Uncertain

-0.010

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.79

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.66

MetaRNN

Pathogenic

0.96

MetaSVM

Pathogenic

0.90

MutationAssessor

Uncertain

2.2

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.68

PROVEAN

Pathogenic

-4.7

REVEL

Pathogenic

0.83

Sift

Benign

0.054

Sift4G

Benign

0.14

Polyphen

1.0

Vest4

0.91

MVP

0.94

MPC

0.80

ClinPred

0.66

GERP RS

5.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.54

gMVP

0.50

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.070

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over