chr9-21971112-G-A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PM5PP5

The NM_000077.5(CDKN2A):​c.247C>T​(p.His83Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H83Q) has been classified as Likely pathogenic.

Frequency

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

Consequence

CDKN2A
NM_000077.5 missense

Scores

6
6
5

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3

Conservation

PhyloP100: 9.23

Publications

127 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 7 ACMG points.

PM1
In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 48 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 chr9-21971110-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 429110.
PP5
Variant 9-21971112-G-A is Pathogenic according to our data. Variant chr9-21971112-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 376307.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CDKN2ANM_000077.5 linkc.247C>T p.His83Tyr missense_variant Exon 2 of 3 ENST00000304494.10 NP_000068.1 P42771-1K7PML8
CDKN2ANM_058195.4 linkc.290C>T p.Ala97Val 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.247C>T p.His83Tyr missense_variant Exon 2 of 3 1 NM_000077.5 ENSP00000307101.5 P42771-1
CDKN2AENST00000579755.2 linkc.290C>T p.Ala97Val missense_variant Exon 2 of 3 1 NM_058195.4 ENSP00000462950.1 Q8N726-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
230846
AF XY:
0.00
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
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: AC0
AF:
0.00
AC:
0
AN:
1451924
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
722664
African (AFR)
AF:
0.00
AC:
0
AN:
33424
American (AMR)
AF:
0.00
AC:
0
AN:
44660
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26072
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39674
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86156
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
44724
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5458
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111508
Other (OTH)
AF:
0.00
AC:
0
AN:
60248
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Melanoma-pancreatic cancer syndrome Pathogenic:1
Mar 08, 2023
Myriad Genetics, Inc.
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely pathogenic. This variant is expected to disrupt protein structure [Myriad internal data]. Functional studies indicate this variant impacts protein function [PMID: 35001868, 9324288]. This variant has been reported in multiple individuals with clinical features of gene-specific disease [PMID: 21462282, 16234564]. -

Melanoma and neural system tumor syndrome Uncertain:1
May 26, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1
Oct 16, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.H83Y variant (also known as c.247C>T), located in coding exon 2 of the CDKN2A gene, results from a C to T substitution at nucleotide position 247. The histidine at codon 83 is replaced by tyrosine, an amino acid with similar properties. This alteration was identified in cohorts with sporadic and multiple melanomas (Begg CB et al. J Natl Cancer Inst, 2005 Oct;97:1507-15; Miller PJ et al. Hum Mutat, 2011 Aug;32:900-11). Protein functional studies have shown this variant to have inhibited CDK4 and CDK6 binding and to have increased proliferation activity compared to wild-type (Yang R et al. Cancer Res, 1995 Jun;55:2503-6; Gombart AF et al. Leukemia, 1997 Oct;11:1673-80; Yarbrough WG et al. J Natl Cancer Inst, 1999 Sep;91:1569-74; Kimura H et al. Elife. 2022 Jan;11). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Another variant at the same codon, p.H83Q (c.249C>A), has been described in families with features of melanoma-pancreatic cancer syndrome (Ambry internal data). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Familial melanoma Uncertain:1
Nov 24, 2023
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 with different open reading frames. Both transcripts have been analyzed. We report either the variant with the higher classification or default to the CDKN2A (p16INK4a) variant. This report therefore includes the details for the CDKN2A (p16INK4a) variant. This sequence change replaces histidine, which is basic and polar, with tyrosine, which is neutral and polar, at codon 83 of the CDKN2A (p16INK4a) protein (p.His83Tyr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with sporadic and multiple primary melanomas (PMID: 16234564, 16896043, 21462282). This variant is also known as c.290C>T (p.Ala97Val) in the CDKN2A (p14ARF) transcript. ClinVar contains an entry for this variant (Variation ID: 376307). 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 disruptive. Experimental studies have shown that this missense change affects CDKN2A (p16INK4a) function (PMID: 7780957, 8521414, 9324288, 10491434). 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
Pathogenic
0.79
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Uncertain
0.030
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Benign
0.077
T;T
Eigen
Pathogenic
0.75
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.55
.;T
M_CAP
Pathogenic
0.31
D
MetaRNN
Uncertain
0.47
T;T
MetaSVM
Uncertain
-0.20
T
PhyloP100
9.2
PROVEAN
Uncertain
-3.1
.;D
REVEL
Uncertain
0.58
Sift
Benign
0.037
.;D
Sift4G
Benign
0.082
T;T
Vest4
0.44
MVP
1.0
ClinPred
0.92
D
GERP RS
5.9
PromoterAI
0.059
Neutral
Varity_R
0.70
Mutation Taster
=1/99
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs121913385; hg19: chr9-21971111; COSMIC: COSV58682852; COSMIC: COSV58682852; API