chr9-21971019-G-A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PS1_ModeratePM1PM2PM5

The NM_000077.5(CDKN2A):​c.340C>T​(p.Pro114Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000656 in 152,346 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P114L) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

CDKN2A
NM_000077.5 missense

Scores

8
6
3

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.18

Publications

32 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_pathogenic. The variant received 8 ACMG points.

PS1
Transcript NM_000077.5 (CDKN2A) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 44 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 chr9-21971018-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 77637.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CDKN2ANM_000077.5 linkc.340C>T p.Pro114Ser missense_variant Exon 2 of 3 ENST00000304494.10 NP_000068.1 P42771-1K7PML8
CDKN2ANM_058195.4 linkc.383C>T p.Ala128Val missense_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.340C>T p.Pro114Ser missense_variant Exon 2 of 3 1 NM_000077.5 ENSP00000307101.5 P42771-1
CDKN2AENST00000579755.2 linkc.383C>T p.Ala128Val missense_variant Exon 2 of 3 1 NM_058195.4 ENSP00000462950.1 Q8N726-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152228
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
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1455220
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
724210
African (AFR)
AF:
0.00
AC:
0
AN:
33452
American (AMR)
AF:
0.00
AC:
0
AN:
44670
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26084
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39682
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86138
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48060
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5196
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111686
Other (OTH)
AF:
0.00
AC:
0
AN:
60252
GnomAD4 genome
AF:
0.00000656
AC:
1
AN:
152346
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74500
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41590
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
292
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Familial melanoma Uncertain:1
Nov 26, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The CDKN2A gene encodes two different proteins, p16INK4a and p14ARF, which are translated from alternative transcripts that have different open reading frames. 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. Experimental studies are conflicting or provide insufficient evidence to determine the effect of p.Pro114Ser variant on p16INK4a protein function (PMID: 9053859, 19260062, 21462282, 23190892, 24659262). The functional impact of p.Ala128Val on p14ARF has not been tested. This missense change has been observed in individual(s) with melanoma (PMID: 11579459, 21462282, 16905682, 17492760, 19484507, 17992122, 17047042, 26775776, 22841127). This variant is not present in population databases (ExAC no frequency). This sequence change replaces proline with serine at codon 114 of the p16INK4a protein (p.Pro114Ser). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and serine. Alternatively, this sequence change replaces alanine with valine at codon 128 of the p14ARF protein (p.Ala128Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.86
BayesDel_addAF
Pathogenic
0.24
D
BayesDel_noAF
Uncertain
0.11
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Benign
0.080
T;T
Eigen
Pathogenic
0.78
Eigen_PC
Pathogenic
0.83
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.57
.;T
M_CAP
Pathogenic
0.61
D
MetaRNN
Uncertain
0.52
D;D
MetaSVM
Uncertain
-0.19
T
PhyloP100
9.2
PROVEAN
Uncertain
-3.1
.;D
REVEL
Uncertain
0.56
Sift
Pathogenic
0.0
.;D
Sift4G
Pathogenic
0.0
D;D
Vest4
0.40
MVP
1.0
ClinPred
0.98
D
GERP RS
5.9
PromoterAI
0.0047
Neutral
Varity_R
0.76
Mutation Taster
=0/100
disease causing

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

Other links and lift over

dbSNP: rs104894104; hg19: chr9-21971018; COSMIC: COSV58704478; API