Is CDKN2A p.Arg99Trp (c.295C>T) pathogenic?

CDKN2A p.Arg99Trp (c.295C>T) is classified Uncertain significance in CDKN2A (ClinVar, Multiple submitters, 3 submitters; last evaluated 2025-10-22). AlphaMissense: ambiguous (0.3409); Very rare (popmax 0.0022%, sas); Associated with hereditary neoplastic syndrome.

What condition is associated with CDKN2A p.Arg99Trp (c.295C>T)?

CDKN2A p.Arg99Trp (c.295C>T) is associated with hereditary neoplastic syndrome, familial melanoma (ClinVar).

How common is CDKN2A p.Arg99Trp (c.295C>T) in the general population?

CDKN2A p.Arg99Trp (c.295C>T) is very rare (popmax 0.0022%, sas) (gnomAD).

What do computational predictors say about CDKN2A p.Arg99Trp (c.295C>T)?

AlphaMissense predicts ambiguous (score 0.3409) — an in-silico prediction, not a clinical call.

CDKN2A p.Arg99Trp

c.295C>T · rs34886500 · VCV483350

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

AlphaMissense

ambiguous

0.3409 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.0022%, sas)

Conditions

hereditary neoplastic syndrome

Computational evidence

Protein change
AlphaMissense	0.3409	ambiguous
REVEL	0.304	indeterminate
SaProt	LLR -12.33	damaging
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 3.6	GERP 1.1, phastCons 1
Regional constraint	o/e 1.13	unconstrained · MANE · 6,595 bp · p 0.04 · regional, not allelic
Overall
CADD	23.8	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0022% South Asian · 2/90,972 alleles

Filtering AF 0.000365% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000137%

Overall 0.000206% 3/1,453,094 alleles · very rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0022%	45,486
European (non-Finnish)	8.48e-05%	1,179,416

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: CDKN2A
Protein: p.Arg99Trp
Coding: c.295C>T
MANE Select: NM_000077
dbSNP: rs34886500
Type: single nucleotide variant
Location: chr9:21971064 (GRCh38)
Gene constraint: LOEUF 0.791 · pLI 0.62 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 77.02 · 5 PDB
Residue 99: an α-helix; a UniProt-annotated variant site (in cmm2; loss of cdk4 binding); a UniProt-annotated variant site (in non-small cell lung carcinoma); a UniProt-annotated variant site (in); the 'disordered' region

Full CDKN2A gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hereditary neoplastic syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: familial melanoma

Similar variants

CDKN2A p.Arg99Pro Likely pathogenic ★★ same residue
CDKN2A p.Arg99Leu Uncertain significance ★★ ⚠ same residue
CDKN2A p.Arg99= Conflicting classifications of pathogenicity ★ same residue
CDKN2A p.Arg99Gln Conflicting classifications of pathogenicity ★ ⚠ same residue
CDKN2A p.Arg99Gly Conflicting classifications of pathogenicity ★ ⚠ same residue
CDKN2A c.150+1G>A Likely pathogenic ★★ same condition
CDKN2A c.150+2T>G Likely pathogenic ★★ same condition
CDKN2A c.151-1G>A Pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/cdkn2a-p-arg99trp (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown