9-21971123-G-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM1PM2BP4

The NM_000077.5(CDKN2A):c.236C>A(p.Thr79Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000187 in 1,603,784 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. T79S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

CDKN2A
NM_000077.5 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 1.75

Publications

14 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: Uncertain_significance. The variant received 3 ACMG points.

PM1

In a hotspot region, there are 16 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 45 uncertain in NM_000077.5

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.34740695).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN2A	NM_000077.5 link	c.236C>A	p.Thr79Asn	missense_variant	Exon 2 of 3	ENST00000304494.10	NP_000068.1
CDKN2A	NM_058195.4 link	c.279C>A	p.His93Gln	missense_variant	Exon 2 of 3	ENST00000579755.2	NP_478102.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKN2A	ENST00000304494.10 link	c.236C>A	p.Thr79Asn	missense_variant	Exon 2 of 3	1	NM_000077.5	ENSP00000307101.5
CDKN2A	ENST00000579755.2 link	c.279C>A	p.His93Gln	missense_variant	Exon 2 of 3	1	NM_058195.4	ENSP00000462950.1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152244

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00

AC:

AN:

229620

AF XY:

0.00

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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:

0.00000138

AC:

AN:

1451540

Hom.:

Cov.:

AF XY:

0.00000277

AC XY:

AN XY:

722510

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33444

American (AMR)

AF:

0.00

AC:

AN:

44644

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26076

East Asian (EAS)

AF:

0.00

AC:

AN:

39668

South Asian (SAS)

AF:

0.00

AC:

AN:

86158

European-Finnish (FIN)

AF:

0.00

AC:

AN:

44324

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5488

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111500

Other (OTH)

AF:

0.00

AC:

AN:

60238

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152244

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74380

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41470

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4838

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68038

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:2

Sep 02, 2018

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Mar 24, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.T79N variant (also known as c.236C>A), located in coding exon 2 of the CDKN2A gene, results from a C to A substitution at nucleotide position 236. The threonine at codon 79 is replaced by asparagine, an amino acid with similar properties. Of note, this variant is also known as c.279C>A p.(H93Q) in the p14(ARF) isoform. This amino acid position is not well 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

Oct 31, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 491570). This variant is also known as c.279C>A (p.His93Gln) in the CDKN2A (p14ARF) transcript. This variant has not been reported in the literature in individuals affected with CDKN2A (p16INK4a)-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 79 of the CDKN2A (p16INK4a) protein (p.Thr79Asn). The CDKN2A gene encodes two different proteins, p16INK4a and p14ARF, which are translated from alternative transcripts with different open reading frames. Both transcripts have been analyzed. We report either the variant with the higher classification or default to the CDKN2A (p16INK4a) variant. This report therefore includes the details for the CDKN2A (p16INK4a) variant.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.55

BayesDel_addAF

Uncertain

0.096

BayesDel_noAF

Benign

-0.10

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.080

T;T

Eigen

Uncertain

0.26

Eigen_PC

Uncertain

0.34

FATHMM_MKL

Uncertain

0.94

LIST_S2

Benign

0.0

.;T

M_CAP

Uncertain

0.28

MetaRNN

Benign

0.35

T;T

MetaSVM

Benign

-0.29

MutationAssessor

Benign

0.0

.;.

PhyloP100

1.7

PROVEAN

Benign

0.0

.;D

REVEL

Benign

0.0

Sift

Pathogenic

0.0

.;T

Sift4G

Benign

0.10

T;T

Vest4

0.17

ClinPred

0.92

GERP RS

5.0

PromoterAI

-0.0081

Neutral

(source)

Varity_R

0.50

Mutation Taster

=8/92

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over