chr9-21970953-C-A

Variant summary

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

The NM_000077.5(CDKN2A):​c.406G>T​(p.Gly136Cys) 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. 13/21 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. G136D) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

CDKN2A
NM_000077.5 missense

Scores

3
15

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.0230

Publications

5 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

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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=0.14866433).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CDKN2ANM_000077.5 linkc.406G>T p.Gly136Cys missense_variant Exon 2 of 3 ENST00000304494.10 NP_000068.1 P42771-1K7PML8
CDKN2ANM_058195.4 linkc.*50G>T 3_prime_UTR_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.406G>T p.Gly136Cys missense_variant Exon 2 of 3 1 NM_000077.5 ENSP00000307101.5 P42771-1
CDKN2AENST00000579755.2 linkc.*50G>T 3_prime_UTR_variant Exon 2 of 3 1 NM_058195.4 ENSP00000462950.1 Q8N726-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1459756
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
726268
African (AFR)
AF:
0.00
AC:
0
AN:
33462
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86224
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51920
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5280
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111998
Other (OTH)
AF:
0.00
AC:
0
AN:
60314
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

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

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1
Apr 26, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.G136C variant (also known as c.406G>T), located in coding exon 2 of the CDKN2A gene, results from a G to T substitution at nucleotide position 406. The glycine at codon 136 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.18
BayesDel_addAF
Uncertain
0.046
T
BayesDel_noAF
Benign
-0.17
CADD
Benign
15
DANN
Uncertain
0.99
DEOGEN2
Benign
0.11
T;.;.;.;.;T;.
Eigen
Benign
-0.92
Eigen_PC
Benign
-0.92
FATHMM_MKL
Benign
0.087
N
LIST_S2
Benign
0.68
T;.;T;.;T;T;T
M_CAP
Uncertain
0.17
D
MetaRNN
Benign
0.15
T;T;T;T;T;T;T
MetaSVM
Benign
-0.43
T
PhyloP100
-0.023
PrimateAI
Benign
0.36
T
PROVEAN
Benign
-1.2
N;.;N;.;.;.;.
REVEL
Benign
0.27
Sift
Benign
0.20
T;.;T;.;.;.;.
Sift4G
Benign
0.19
T;T;T;T;T;T;T
Polyphen
0.016
B;.;.;.;.;.;.
Vest4
0.32
MutPred
0.41
Loss of disorder (P = 0.026);.;Loss of disorder (P = 0.026);.;.;.;.;
MVP
0.82
MPC
1.2
ClinPred
0.20
T
GERP RS
1.7
PromoterAI
-0.094
Neutral
Varity_R
0.091
gMVP
0.63
Mutation Taster
=4/96
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: rs777840257; hg19: chr9-21970952; API