chr16-47669217-A-A

Variant names:

• chr16-47669217-A-A
• NM_000293.3:c.

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The ENST00000323584.10(PHKB):​c. variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PHKB ENST00000323584.10 splice_donor, intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.26
• Publications: 0 publications found

Genes affected

PHKB (HGNC:8927): (phosphorylase kinase regulatory subunit beta) 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, encoded by this gene, which is a member of the phosphorylase b kinase regulatory subunit family. The gamma subunit also includes the skeletal muscle and hepatic isoforms, 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 9B, also known as phosphorylase kinase deficiency of liver and muscle. Alternatively spliced transcript variants encoding different isoforms have been identified in this gene. Two pseudogenes have been found on chromosomes 14 and 20, respectively.[provided by RefSeq, Feb 2010]

PHKB Gene-Disease associations (from GenCC):

• glycogen storage disease IXb

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.06185253 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7.8, offset of 0 (no position change), new splice context is: taaaattctgccacttgtAGgta. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000323584.10. 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
	PHKB	NM_000293.3	MANE Select	c.		intron	N/A	NP_000284.1	Q93100-1
	PHKB	NM_001363837.1		c.		intron	N/A	NP_001350766.1	Q93100-3
	PHKB	NM_001031835.3		c.		intron	N/A	NP_001027005.1	Q93100-4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PHKB	ENST00000323584.10	TSL:1 MANE Select	c.		splice_donor intron	N/A	ENSP00000313504.5	Q93100-1
	PHKB	ENST00000566044.5	TSL:1	c.		splice_donor intron	N/A	ENSP00000456729.1	Q93100-4
	PHKB	ENST00000940565.1		c.		splice_donor intron	N/A	ENSP00000610624.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr16-47703128;