9-21974734-G-C

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_000077.5(CDKN2A):c.94C>G(p.Leu32Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,394 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 (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CDKN2A
NM_000077.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.27

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 links:

ENSG00000264545 (HGNC:):

ENSG00000264545 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1

In a repeat ANK 1 (size 29) in uniprot entity CDN2A_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_000077.5

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.758

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN2A	NM_000077.5 link	c.94C>G	p.Leu32Val	missense_variant	Exon 1 of 3	ENST00000304494.10	NP_000068.1	P42771-1K7PML8
CDKN2A	NM_058195.4 link	c.194-3526C>G		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.94C>G	p.Leu32Val	missense_variant	Exon 1 of 3	1	NM_000077.5	ENSP00000307101.5		P42771-1
CDKN2A	ENST00000579755.2 link	c.194-3526C>G		intron_variant	Intron 1 of 2	1	NM_058195.4	ENSP00000462950.1		Q8N726-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000821

AC:

AN:

243524

Hom.:

AF XY:

0.00

AC XY:

AN XY:

133218

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000580

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS 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:

0.00000205

AC:

AN:

1460394

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726538

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000830

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Melanoma and neural system tumor syndrome

Uncertain:1

Nov 13, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome

Uncertain:1

Jul 22, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L32V variant (also known as c.94C>G), located in coding exon 1 of the CDKN2A gene, results from a C to G substitution at nucleotide position 94. The leucine at codon 32 is replaced by valine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Familial melanoma

Uncertain:1

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 32 of the CDKN2A (p16INK4a) protein (p.Leu32Val). This variant is present in population databases (rs745827714, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with CDKN2A (p16INK4a)-related conditions. ClinVar contains an entry for this variant (Variation ID: 532278). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. This variant disrupts the p.Leu32 amino acid residue in CDKN2A (p16INK4a). Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8595405, 16905682, 17047042, 19712690, 20340136, 28592523). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.30

BayesDel_addAF

Uncertain

0.044

BayesDel_noAF

Uncertain

0.0

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.44

T;T;.

Eigen

Pathogenic

0.80

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.89

D;D;D

M_CAP

Pathogenic

0.53

MetaRNN

Pathogenic

0.76

D;D;D

MetaSVM

Uncertain

0.22

PrimateAI

Uncertain

0.62

PROVEAN

Uncertain

-2.5

D;.;D

REVEL

Pathogenic

0.67

Sift

Uncertain

0.0040

D;.;D

Sift4G

Uncertain

0.0060

D;D;D

Polyphen

1.0

D;.;.

Vest4

0.45

MutPred

0.57

Gain of MoRF binding (P = 0.0908);Gain of MoRF binding (P = 0.0908);Gain of MoRF binding (P = 0.0908);

MVP

0.91

MPC

1.2

ClinPred

0.94

GERP RS

4.9

Varity_R

0.42

gMVP

0.94

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over