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Gene

CDKN2A

cyclin dependent kinase inhibitor 2A

Summary

Cytogenetic location
9p21.3
Coordinates
Chromosome 9: 21,967,752–21,974,857 (GRCh38)
Exons
3 exons across 7.1 kb
Protein
156 amino acids
Inheritance
Autosomal dominant
Also known as
CDK4I, p16, INK4a, MTS1, CMM2, ARF, p19, p14, INK4, p16INK4a, p19Arf, p14ARF, P16-INK4A, CAI2
Previous symbols
CDKN2, MLM
MANE Select transcript
ENST00000304494.10NM_000077.5
Locus type
gene with protein product
  • Very high
  • Confident
  • Low
  • Very low

Reference genomeGRCh38

Positions on gene and variant pages follow this choice, in this browser.

Curated report relevant to this gene

  • Melanoma

    • Familial atypical multiple mole melanoma syndromeAutosomal dominant

      Many atypical moles with a high risk of melanoma, often caused by CDKN2A variants that also raise pancreatic cancer risk.

      • ClinGen rates the link definitive
      • 4 GenCC submitters rate it definitive or strong
      What knowing changes

      Regular full skin examinations and, where a CDKN2A variant is found, consideration of pancreatic cancer surveillance.

    • Susceptibility to familial cutaneous melanomaAutosomal dominant

      Inherited melanoma susceptibility caused by variants in genes such as CDKN2A, CDK4, MITF and POT1.

      • 1 GenCC submitter rates it definitive or strong
      What knowing changes

      Regular full skin examinations, sun protection and, for CDKN2A carriers, consideration of pancreatic surveillance.

Inheritance

Autosomal dominant
One changed copy, from either parent, is enough. A parent who has one passes it on to each child with a one-in-two chance.

How CDKN2A is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Stretches short reads find hard
Chromosome 9, with a bracket where CDKN2A sits. CDKN2A and 4 genes near it on chromosome 9, from 21,471,305 to 22,471,304.Chromosome 99p21.3p24.3p24.2p24.1p23p22.3p22.2p22.1p21.3p21.2p21.1p13.3p13.2p13.1p12p11.2p11.1q11q12q13q21.11q21.12q21.13q21.2q21.31q21.32q21.33q22.1q22.2q22.31q22.32q22.33q31.1q31.2q31.3q32q33.1q33.2q33.3q34.11q34.12q34.13q34.2q34.321.6 Mb21.8 Mb22 Mb22.2 Mb22.4 MbIFNE: 21,480,839–21,482,313, reverse strandIFNEMTAP: 21,802,614–21,937,651, forward strandMTAPCDKN2A: 21,967,752–21,974,857, reverse strandCDKN2ACDKN2B: 22,002,900–22,009,325, reverse strandCDKN2BDMRTA1: 22,446,777–22,468,199, forward strandDMRTA1Diagram of CDKN2A: 3 exons on the reverse strand of chromosome 9Exon 2: 79 known disease-causing sitesExon 1: 44 known disease-causing sitesExon 3: 21,967,752–21,968,242, 491 basesExon 2: 21,970,902–21,971,208, 307 basesExon 1: 21,974,678–21,974,857, 180 bases3215′3′

Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.

Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).

Nearby genes from Ensembl release 116, on GRCh38.

Exons make up 1 kb of the gene's 7.1 kb; 471 of those bases code for the protein.

How a genome test reads CDKN2A

161

positions in CDKN2A where ClinVar classes a change as pathogenic or likely pathogenic

1 of them (0.6%) falls in a region short reads find hard.

  • Low mappability (1 site)Regions where 100 bp or 250 bp reads cannot be placed uniquely.

A whole genome covers all 7.1 kb of CDKN2A, introns included, not only the 1 kb of exons.

Where this comes from

  • HGNC: the gene's symbol, name, other symbols and location.
  • MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
  • GenCC and ClinGen, released 2026-10-16: which conditions the gene is linked to, and how strongly.
  • The ACMG secondary findings list, SF v3.2.
  • ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
  • The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
  • Data release 2026.10.16-c6eea6bf.

Cite this page

APA

Dante Labs. (n.d.). CDKN2A gene: cyclin dependent kinase inhibitor 2A. Retrieved 16 October 2026, from https://dantelabs.com/genes/cdkn2a

Vancouver

Dante Labs. CDKN2A gene: cyclin dependent kinase inhibitor 2A [Internet]. [cited 16 October 2026]. Available from: https://dantelabs.com/genes/cdkn2a

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