rs137852286

Variant names:

• chrX-18908865-G-A
• rs137852286
• NM_000292.3:c.2296C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_000292.3(PHKA2):​c.2296C>T​(p.Gln766*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: PHKA2 NM_000292.3 stop_gained
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 6.49
• Publications: 2 publications found

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 Gene-Disease associations (from GenCC):

• glycogen storage disease IXa1

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

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

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-18908865-G-A is Pathogenic according to our data. Variant chrX-18908865-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 10528.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000292.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PHKA2	NM_000292.3	MANE Select	c.2296C>T	p.Gln766*	stop_gained	Exon 21 of 33	NP_000283.1	P46019
	PHKA2	NM_001440805.1		c.2296C>T	p.Gln766*	stop_gained	Exon 21 of 33	NP_001427734.1
	PHKA2	NM_001440800.1		c.2296C>T	p.Gln766*	stop_gained	Exon 21 of 32	NP_001427729.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PHKA2	ENST00000379942.5	TSL:1 MANE Select	c.2296C>T	p.Gln766*	stop_gained	Exon 21 of 33	ENSP00000369274.4	P46019
	PHKA2	ENST00000897868.1		c.2296C>T	p.Gln766*	stop_gained	Exon 21 of 33	ENSP00000567927.1
	PHKA2	ENST00000954730.1		c.2281C>T	p.Gln761*	stop_gained	Exon 21 of 33	ENSP00000624789.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Glycogen storage disease IXa1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	37
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		6.5
Vest4		0.98
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=3/197	disease causing (ClinVar)

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: rs137852286; hg19: chrX-18926983;