9-21974724-C-A

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1PM2PM5PP3_Strong

The NM_000077.5(CDKN2A):c.104G>T(p.Gly35Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,806 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G35A) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

CDKN2A
NM_000077.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.65

Publications

31 publications found

Variant links:

Genes affected

CDKN2A (HGNC:1787): (cyclin dependent kinase inhibitor 2A) This gene generates several transcript variants which differ in their first exons. At least three alternatively spliced variants encoding distinct proteins have been reported, two of which encode structurally related isoforms known to function as inhibitors of CDK4 kinase. The remaining transcript includes an alternate first exon located 20 Kb upstream of the remainder of the gene; this transcript contains an alternate open reading frame (ARF) that specifies a protein which is structurally unrelated to the products of the other variants. This ARF product functions as a stabilizer of the tumor suppressor protein p53 as it can interact with, and sequester, the E3 ubiquitin-protein ligase MDM2, a protein responsible for the degradation of p53. In spite of the structural and functional differences, the CDK inhibitor isoforms and the ARF product encoded by this gene, through the regulatory roles of CDK4 and p53 in cell cycle G1 progression, share a common functionality in cell cycle G1 control. This gene is frequently mutated or deleted in a wide variety of tumors, and is known to be an important tumor suppressor gene. [provided by RefSeq, Sep 2012]

CDKN2A Gene-Disease associations (from GenCC):

melanoma, cutaneous malignant, susceptibility to, 2
Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
melanoma-pancreatic cancer syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics
familial atypical multiple mole melanoma syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
melanoma and neural system tumor syndrome
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

CDKN2A links:

ENSG00000264545 (HGNC:):

ENSG00000264545 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 46 uncertain in NM_000077.5

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr9-21974724-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 463481.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.993

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN2A	NM_000077.5 link	c.104G>T	p.Gly35Val	missense_variant	Exon 1 of 3	ENST00000304494.10	NP_000068.1	P42771-1K7PML8
CDKN2A	NM_058195.4 link	c.194-3516G>T		intron_variant	Intron 1 of 2	ENST00000579755.2	NP_478102.2	Q8N726-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKN2A	ENST00000304494.10 link	c.104G>T	p.Gly35Val	missense_variant	Exon 1 of 3	1	NM_000077.5	ENSP00000307101.5		P42771-1
CDKN2A	ENST00000579755.2 link	c.194-3516G>T		intron_variant	Intron 1 of 2	1	NM_058195.4	ENSP00000462950.1		Q8N726-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000408

AC:

AN:

244916

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460806

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726730

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.0000224

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86246

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52574

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111834

Other (OTH)

AF:

0.00

AC:

AN:

60360

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:1

Jun 11, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.G35V variant (also known as c.104G>T), located in coding exon 1 of the CDKN2A gene, results from a G to T substitution at nucleotide position 104. The glycine at codon 35 is replaced by valine, an amino acid with dissimilar properties. This alteration demonstrated loss of CDK4 binding in a functional assay (Kannengiesser C et al. Hum Mutat, 2009 Apr;30:564-74). This variant was reported in individual(s) with features consistent with melanoma-pancreatic cancer syndrome (Maubec E et al. J Am Acad Dermatol, 2012 Dec;67:1257-64). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Familial melanoma

Uncertain:1

May 12, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant has been reported in individuals affected with familial melanoma (PMID: 19260062, 21462282) and cutaneous melanoma (PMID: 22841127, 15937071). In summary, this variant is a rare missense change that has been observed in affected individuals and has been shown to impact some aspects of protein function in vitro. However, the evidence is insufficient to prove conclusively that this variant causes disease. For these reasons, this change has been classified as a Variant of Uncertain Significance. This variant is not present in population databases (ExAC no frequency). Experimental studies in vitro have shown that this missense change impairs CDK4 binding and the ability of CDKN2A to inhibit proliferation of human diploid fibroblasts (PMID: 19260062, 24659262), but does not greatly differ from wild-type CDKN2A in its effect on cell cycle distribution or the generation of reactive oxygen species in a cell culture model (PMID: 23190892). This sequence change replaces glycine with valine at codon 35 of the CDKN2A protein (p.Gly35Val). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and valine. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.85

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.32

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.59

D;T;.

Eigen

Pathogenic

0.92

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Uncertain

0.94

LIST_S2

Uncertain

0.91

D;D;D

M_CAP

Pathogenic

0.75

MetaRNN

Pathogenic

0.99

D;D;D

MetaSVM

Pathogenic

1.0

PhyloP100

2.6

PrimateAI

Uncertain

0.60

PROVEAN

Pathogenic

-6.0

D;.;D

REVEL

Pathogenic

0.86

Sift

Benign

0.037

D;.;D

Sift4G

Uncertain

0.028

D;D;D

Polyphen

1.0

D;.;.

Vest4

0.82

MutPred

0.90

Loss of catalytic residue at G35 (P = 0.0465);Loss of catalytic residue at G35 (P = 0.0465);Loss of catalytic residue at G35 (P = 0.0465);

MVP

0.99

MPC

1.4

ClinPred

1.0

GERP RS

4.9

PromoterAI

0.11

Neutral

(source)

Varity_R

0.46

gMVP

0.98

Mutation Taster

=0/100

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over