9-21974803-T-G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_000077.5(CDKN2A):​c.25A>C​(p.Met9Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. 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: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

CDKN2A
NM_000077.5 missense

Scores

1
1
16

Clinical Significance

Not reported in ClinVar

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: Uncertain_significance. The variant received 2 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
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.16016015).

Transcripts

RefSeq

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

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000863
AC:
2
AN:
231706
AF XY:
0.0000156
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000293
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
Data not reliable, filtered out with message: AS_VQSR
AF:
0.00000138
AC:
2
AN:
1452386
Hom.:
0
Cov.:
32
AF XY:
0.00000277
AC XY:
2
AN XY:
722718
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
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:
0.00
AC:
0
AN:
1110374
Other (OTH)
AF:
0.00
AC:
0
AN:
60138
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
1
1
2
2
3
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
Cov.:
32
ExAC
AF:
0.00000855
AC:
1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.12
BayesDel_addAF
Benign
-0.18
T
BayesDel_noAF
Benign
-0.39
CADD
Benign
15
DANN
Benign
0.52
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
0.55
D
MetaRNN
Benign
0.16
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
0.033
T
GERP RS
-0.75
PromoterAI
-0.083
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