CDKN1B
Chr 12ADcyclin dependent kinase inhibitor 1B
Also known as: CDKN4, KIP1, MEN1B, MEN4, P27KIP1
This gene encodes a cyclin-dependent kinase inhibitor, which shares a limited similarity with CDK inhibitor CDKN1A/p21. The encoded protein binds to and prevents the activation of cyclin E-CDK2 or cyclin D-CDK4 complexes, and thus controls the cell cycle progression at G1. The degradation of this protein, which is triggered by its CDK dependent phosphorylation and subsequent ubiquitination by SCF complexes, is required for the cellular transition from quiescence to the proliferative state. Mutations in this gene are associated with multiple endocrine neoplasia type IV (MEN4). [provided by RefSeq, Apr 2014]
Definitive — sufficient evidence for diagnostic panels
2 total gene-disease associations curated
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Tolerant to missense variation
This gene — mechanism propensity
The highest-scoring mechanism for this gene is loss-of-function (haploinsufficiency).
Literature Evidence
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.
References
ClinVar Variant Classifications
1121 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 97 | 0 | 3 | 0 | 100 |
Likely Pathogenic | 20 | 0 | 1 | 0 | 21 |
VUS | 39 | 505 | 56 | 2 | 602 |
Likely Benign | 0 | 10 | 47 | 210 | 267 |
Benign | 0 | 3 | 15 | 2 | 20 |
Conflicting | — | 106 | |||
| Total | 156 | 518 | 122 | 214 | 1,116 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →47 pathogenic / likely-pathogenic (of 52) ClinVar copy-number / structural variants overlap CDKN1B — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →
Protein Context — Lollipop Plot
CDKN1B · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools