rs772411700

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM1BS2

The NM_000077.5(CDKN2A):​c.224C>T​(p.Pro75Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000564 in 1,596,408 control chromosomes in the GnomAD database, including 1 homozygotes. 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. P75S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000048 ( 1 hom. )

Consequence

CDKN2A
NM_000077.5 missense

Scores

3
12
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 2.64

Publications

10 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM1
In a hotspot region, there are 14 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 47 uncertain in NM_000077.5
BS2
High AC in GnomAdExome4 at 7 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CDKN2ANM_000077.5 linkc.224C>T p.Pro75Leu missense_variant Exon 2 of 3 ENST00000304494.10 NP_000068.1 P42771-1K7PML8
CDKN2ANM_058195.4 linkc.267C>T p.Pro89Pro synonymous_variant Exon 2 of 3 ENST00000579755.2 NP_478102.2 Q8N726-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CDKN2AENST00000304494.10 linkc.224C>T p.Pro75Leu missense_variant Exon 2 of 3 1 NM_000077.5 ENSP00000307101.5 P42771-1
CDKN2AENST00000579755.2 linkc.267C>T p.Pro89Pro synonymous_variant Exon 2 of 3 1 NM_058195.4 ENSP00000462950.1 Q8N726-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152202
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000463
AC:
1
AN:
215810
AF XY:
0.00000835
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000301
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:
0.00000485
AC:
7
AN:
1444206
Hom.:
1
Cov.:
31
AF XY:
0.00000696
AC XY:
5
AN XY:
718524
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33306
American (AMR)
AF:
0.000114
AC:
5
AN:
43978
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25934
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39332
South Asian (SAS)
AF:
0.0000234
AC:
2
AN:
85566
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
41490
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5570
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1109090
Other (OTH)
AF:
0.00
AC:
0
AN:
59940
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000131
AC:
2
AN:
152202
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74356
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41460
American (AMR)
AF:
0.000131
AC:
2
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000842
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2
Mar 05, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.P75L variant (also known as c.224C>T), located in coding exon 2 of the CDKN2A gene, results from a C to T substitution at nucleotide position 224. The proline at codon 75 is replaced by leucine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Of note, this alteration is also known as c.267C>T in the p14(ARF) isoform. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Oct 02, 2023
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces proline with leucine at codon 75 of the CDKN2A (p16INK4A) protein. Computational prediction tool is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/215810 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not specified Uncertain:1
Mar 04, 2025
Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Familial melanoma Uncertain:1
Sep 13, 2023
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. 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. ClinVar contains an entry for this variant (Variation ID: 483326). This variant has not been reported in the literature in individuals affected with CDKN2A (p16INK4a)-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 75 of the CDKN2A (p16INK4a) protein (p.Pro75Leu). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.26
BayesDel_addAF
Pathogenic
0.22
D
BayesDel_noAF
Uncertain
0.070
CADD
Uncertain
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.53
D;T;.;.;.;.;T;.
Eigen
Uncertain
0.53
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Uncertain
0.94
D;D;.;D;.;D;D;D
M_CAP
Uncertain
0.28
D
MetaRNN
Uncertain
0.47
T;T;T;T;T;T;T;T
MetaSVM
Pathogenic
0.81
D
PhyloP100
2.6
PrimateAI
Benign
0.46
T
PROVEAN
Pathogenic
-6.3
D;.;.;D;.;.;.;.
REVEL
Uncertain
0.52
Sift
Uncertain
0.028
D;.;.;D;.;.;.;.
Sift4G
Uncertain
0.052
T;T;D;D;D;D;D;D
Polyphen
1.0
D;.;.;.;.;.;.;.
Vest4
0.30
MutPred
0.33
Loss of disorder (P = 0.0374);Loss of disorder (P = 0.0374);.;Loss of disorder (P = 0.0374);.;.;.;.;
MVP
1.0
MPC
1.2
ClinPred
0.89
D
GERP RS
4.9
PromoterAI
-0.0056
Neutral
Varity_R
0.44
gMVP
0.78
Mutation Taster
=10/90
disease causing

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

Other links and lift over

dbSNP: rs772411700; hg19: chr9-21971134; COSMIC: COSV58688496; API