PHKB

Chr 16AR

phosphorylase kinase regulatory subunit beta

The PHKB protein serves as the regulatory beta subunit of phosphorylase kinase, a 16-subunit enzyme that controls glycogen breakdown through phosphorylation-mediated regulation. Mutations in PHKB cause glycogen storage disease type 9B (phosphorylase kinase deficiency of liver and muscle) with autosomal recessive inheritance. The pathogenic mechanism involves gain-of-function effects that disrupt normal glycogen metabolism regulation.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
GOFmechanismARLOEUF 0.841 OMIM phenotype
Clinical SummaryPHKB
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Gene-Disease Validity (ClinGen)
glycogen storage disease IXb · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.84LOEUF
pLI 0.000
Z-score 2.66
OE 0.65 (0.510.84)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.30Z-score
OE missense 0.97 (0.901.03)
568 obs / 588.4 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.65 (0.510.84)
00.351.4
Missense OE0.97 (0.901.03)
00.61.4
Synonymous OE0.94
01.21.6
LoF obs/exp: 44 / 67.6Missense obs/exp: 568 / 588.4Syn Z: 0.74
DN
0.6065th %ile
GOF
0.6639th %ile
LOF
0.3746th %ile

The highest-scoring mechanism for this gene is gain-of-function.

GOFprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

PHKB · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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