chrX-72578892-T-C

Variant names:

• chrX-72578892-T-C
• rs1380630404
• NM_002637.4:c.*2110A>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BS2_Supporting

The NM_002637.4(PHKA1):​c.*2110A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000268 in 112,032 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 2 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.000027 (0 hom., 2 hem., cov: 23)
• Consequence: PHKA1 NM_002637.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.20
• Publications: 0 publications found

Genes affected

PHKA1 (HGNC:8925): (phosphorylase kinase regulatory subunit alpha 1) 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 skeletal muscle 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 9D, also known as X-linked muscle glycogenosis. Alternatively spliced transcript variants encoding different isoforms have been identified in this gene. A pseudogene has been found on chromosome 1.[provided by RefSeq, Feb 2010]

PHKA1 Gene-Disease associations (from GenCC):

• glycogen storage disease IXd

  Inheritance: XL, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BS2: High Hemizygotes in GnomAd4 at 2 XL,AR geneVariant has number of hemizygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002637.4. 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
	PHKA1	NM_002637.4	MANE Select	c.*2110A>G		3_prime_UTR	Exon 32 of 32	NP_002628.2	P46020-1
	PHKA1	NM_001431068.1		c.*2110A>G		3_prime_UTR	Exon 33 of 33	NP_001417997.1	A6NMN0
	PHKA1	NM_001122670.2		c.*2110A>G		3_prime_UTR	Exon 31 of 31	NP_001116142.1	P46020-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PHKA1	ENST00000373542.9	TSL:1 MANE Select	c.*2110A>G		3_prime_UTR	Exon 32 of 32	ENSP00000362643.4	P46020-1
	PHKA1	ENST00000339490.7	TSL:1	c.*2110A>G		3_prime_UTR	Exon 31 of 31	ENSP00000342469.3	P46020-2
	PHKA1	ENST00000541944.5	TSL:1	c.*2110A>G		3_prime_UTR	Exon 30 of 30	ENSP00000441251.1	P46020-3

Frequencies

GnomAD3 genomes AF: 0.0000268 AC: 3 AN: 112032 Hom.: 0 Cov.: 23

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000284

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 0

GnomAD4 genome AF: 0.0000268 AC: 3 AN: 112032 Hom.: 0 Cov.: 23 AF XY: 0.0000585 AC XY: 2 AN XY: 34200

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 30842

American (AMR) AF: 0.000284 AC: 3 AN: 10556

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2647

East Asian (EAS) AF: 0.00 AC: 0 AN: 3614

South Asian (SAS) AF: 0.00 AC: 0 AN: 2705

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 5985

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 238

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 53254

Other (OTH) AF: 0.00 AC: 0 AN: 1503

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000378

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	8.6
DANN	Benign	0.70
PhyloP100		1.2

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: rs1380630404; hg19: chrX-71798742;