9-21974814-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000077.5(CDKN2A):​c.14C>A​(p.Ala5Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000659 in 151,816 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 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. A5V) has been classified as Uncertain significance.

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

3
14

Clinical Significance

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

Conservation

PhyloP100: -0.408

Publications

1 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: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.09787762).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000077.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CDKN2A
NM_000077.5
MANE Select
c.14C>Ap.Ala5Glu
missense
Exon 1 of 3NP_000068.1
CDKN2A
NM_058195.4
MANE Plus Clinical
c.194-3606C>A
intron
N/ANP_478102.2
CDKN2A
NM_001195132.2
c.14C>Ap.Ala5Glu
missense
Exon 1 of 4NP_001182061.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CDKN2A
ENST00000304494.10
TSL:1 MANE Select
c.14C>Ap.Ala5Glu
missense
Exon 1 of 3ENSP00000307101.5
CDKN2A
ENST00000498124.1
TSL:1
c.14C>Ap.Ala5Glu
missense
Exon 1 of 4ENSP00000418915.1
CDKN2A
ENST00000380151.3
TSL:1
n.14C>A
non_coding_transcript_exon
Exon 1 of 3ENSP00000369496.3

Frequencies

GnomAD3 genomes
AF:
0.00000659
AC:
1
AN:
151816
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:
1448558
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
720674
African (AFR)
AF:
0.00
AC:
0
AN:
33330
American (AMR)
AF:
0.00
AC:
0
AN:
44218
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25892
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39564
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85878
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
45118
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5466
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1109086
Other (OTH)
AF:
0.00
AC:
0
AN:
60006
GnomAD4 genome
AF:
0.00000659
AC:
1
AN:
151816
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74134
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41322
American (AMR)
AF:
0.00
AC:
0
AN:
15208
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5156
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4806
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10588
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67954
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

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

Sep 21, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A5E variant (also known as c.14C>A), located in coding exon 1 of the CDKN2A gene, results from a C to A substitution at nucleotide position 14. The alanine at codon 5 is replaced by glutamic acid, an amino acid with dissimilar properties. This amino acid position is poorly 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.

Familial melanoma Uncertain:1
May 19, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine with glutamic acid at codon 5 of the CDKN2A (p16INK4a) protein (p.Ala5Glu). The alanine residue is weakly conserved and there is a moderate physicochemical difference between alanine and glutamic acid. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with CDKN2A (p16INK4a)-related conditions. ClinVar contains an entry for this variant (Variation ID: 489864). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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 v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.099
BayesDel_addAF
Benign
-0.080
T
BayesDel_noAF
Benign
-0.35
CADD
Benign
9.4
DANN
Benign
0.73
DEOGEN2
Benign
0.11
T
Eigen
Benign
-1.3
Eigen_PC
Benign
-1.3
FATHMM_MKL
Benign
0.076
N
LIST_S2
Benign
0.37
T
M_CAP
Benign
0.0082
T
MetaRNN
Benign
0.098
T
MetaSVM
Benign
-0.95
T
PhyloP100
-0.41
PrimateAI
Uncertain
0.61
T
PROVEAN
Benign
-1.1
N
REVEL
Benign
0.18
Sift
Uncertain
0.013
D
Sift4G
Uncertain
0.031
D
Polyphen
0.0010
B
Vest4
0.23
MutPred
0.19
Loss of glycosylation at S8 (P = 0.135)
MVP
0.71
MPC
0.50
ClinPred
0.058
T
GERP RS
-0.70
PromoterAI
-0.042
Neutral
Varity_R
0.12
gMVP
0.70
Mutation Taster
=23/77
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: rs1554656700; hg19: chr9-21974813; API