rs748866274

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM1BP4_ModerateBS2

The NM_000077.5(CDKN2A):​c.25A>T​(p.Met9Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000561 in 1,604,328 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict 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. M9K) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

CDKN2A
NM_000077.5 missense

Scores

1
1
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 0.477

Publications

2 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 -4 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 12 benign, 35 uncertain in NM_000077.5
BP4
Computational evidence support a benign effect (MetaRNN=0.16806144).
BS2
High AC in GnomAdExome4 at 8 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CDKN2ANM_000077.5 linkc.25A>T p.Met9Leu missense_variant Exon 1 of 3 ENST00000304494.10 NP_000068.1 P42771-1K7PML8
CDKN2ANM_058195.4 linkc.194-3595A>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
CDKN2AENST00000304494.10 linkc.25A>T p.Met9Leu missense_variant Exon 1 of 3 1 NM_000077.5 ENSP00000307101.5 P42771-1
CDKN2AENST00000579755.2 linkc.194-3595A>T intron_variant Intron 1 of 2 1 NM_058195.4 ENSP00000462950.1 Q8N726-1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151942
Hom.:
0
Cov.:
32
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
GnomAD4 exome
AF:
0.00000551
AC:
8
AN:
1452386
Hom.:
0
Cov.:
32
AF XY:
0.00000830
AC XY:
6
AN XY:
722718
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33402
American (AMR)
AF:
0.0000225
AC:
1
AN:
44512
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25998
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39636
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86084
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
46616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5626
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1110374
Other (OTH)
AF:
0.00
AC:
0
AN:
60138
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.00000658
AC:
1
AN:
151942
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74204
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41388
American (AMR)
AF:
0.00
AC:
0
AN:
15212
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5166
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67966
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2
Jul 11, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.M9L variant (also known as c.25A>T), located in coding exon 1 of the CDKN2A gene, results from an A to T substitution at nucleotide position 25. The methionine at codon 9 is replaced by leucine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Feb 19, 2025
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The CDKN2A locus encodes two different gene products, p16INK4a and p14ARF (https://www.ncbi.nlm.nih.gov/books/NBK7030/). This missense variant replaces methionine with leucine at codon 9 of the CDKN2A (p16INK4A) protein. Computational prediction suggests that this variant may not impact protein structure and function. 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 1/31298 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
Sep 08, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Melanoma and neural system tumor syndrome Uncertain:1
Jul 13, 2021
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

not provided Uncertain:1
Dec 02, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 30981987, 30857943) -

Familial melanoma Uncertain:1
Nov 04, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 9 of the CDKN2A (p16INK4a) protein (p.Met9Leu). This variant is not present in population databases (gnomAD no frequency). 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: 483321). 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 tolerated. 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
0.12
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.39
CADD
Benign
15
DANN
Benign
0.53
DEOGEN2
Benign
0.12
T;T;.
Eigen
Benign
-1.3
Eigen_PC
Benign
-1.4
FATHMM_MKL
Benign
0.13
N
LIST_S2
Benign
0.42
T;T;T
M_CAP
Pathogenic
0.56
D
MetaRNN
Benign
0.17
T;T;T
MetaSVM
Benign
-0.92
T
PhyloP100
0.48
PrimateAI
Uncertain
0.69
T
PROVEAN
Benign
-1.1
N;.;N
REVEL
Benign
0.15
Sift
Benign
0.14
T;.;T
Sift4G
Benign
0.35
T;T;T
Polyphen
0.0010
B;.;.
Vest4
0.20
MutPred
0.16
Gain of glycosylation at S8 (P = 0.0779);Gain of glycosylation at S8 (P = 0.0779);Gain of glycosylation at S8 (P = 0.0779);
MVP
0.79
MPC
0.37
ClinPred
0.064
T
GERP RS
-0.75
PromoterAI
-0.12
Neutral
Varity_R
0.24
gMVP
0.82
Mutation Taster
=67/33
polymorphism

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: rs748866274; hg19: chr9-21974802; API