chr9-21974790-G-T

Position:

chr9-21974790-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The ENST00000304494.10(CDKN2A):c.38C>A(p.Ala13Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,455,180 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. A13S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

CDKN2A
ENST00000304494.10 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.653

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 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 17 uncertain in ENST00000304494.10

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.22705403).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDKN2A	NM_000077.5 linkuse as main transcript	c.38C>A	p.Ala13Asp	missense_variant	1/3	ENST00000304494.10	NP_000068.1
CDKN2A	NM_058195.4 linkuse as main transcript	c.194-3582C>A		intron_variant		ENST00000579755.2	NP_478102.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDKN2A	ENST00000304494.10 linkuse as main transcript	c.38C>A	p.Ala13Asp	missense_variant	1/3	1	NM_000077.5	ENSP00000307101	P2	P42771-1
CDKN2A	ENST00000579755.2 linkuse as main transcript	c.194-3582C>A		intron_variant		1	NM_058195.4	ENSP00000462950		Q8N726-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000853

AC:

AN:

234560

Hom.:

AF XY:

0.0000155

AC XY:

AN XY:

129370

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000112

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1455180

Hom.:

Cov.:

AF XY:

0.00000276

AC XY:

AN XY:

724214

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

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

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 02, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jun 13, 2024	The p.A13D variant (also known as c.38C>A), located in coding exon 1 of the CDKN2A gene, results from a C to A substitution at nucleotide position 38. The alanine at codon 13 is replaced by aspartic acid, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Familial melanoma

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 07, 2023

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. 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. ClinVar contains an entry for this variant (Variation ID: 483348). This variant has not been reported in the literature in individuals affected with CDKN2A (p16INK4a)-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.01%). This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 13 of the CDKN2A (p16INK4a) protein (p.Ala13Asp). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.37

BayesDel_addAF

Benign

-0.14

BayesDel_noAF

Benign

-0.21

CADD

Benign

DANN

Uncertain

0.98

DEOGEN2

Benign

0.15

T;T;.

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.16

LIST_S2

Benign

0.71

T;T;T

M_CAP

Pathogenic

0.41

MetaRNN

Benign

0.23

T;T;T

MetaSVM

Benign

-0.80

MutationTaster

Benign

1.0

D;D;D;D;D;N;N;N;N

PrimateAI

Uncertain

0.75

PROVEAN

Benign

-0.71

N;.;N

REVEL

Uncertain

0.33

Sift

Benign

0.078

T;.;T

Sift4G

Benign

0.40

T;T;T

Polyphen

0.011

B;.;.

Vest4

0.34

MutPred

0.26

Loss of MoRF binding (P = 0.0357);Loss of MoRF binding (P = 0.0357);Loss of MoRF binding (P = 0.0357);

MVP

0.81

MPC

1.4

ClinPred

0.13

GERP RS

0.45

Varity_R

0.35

gMVP

0.88

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over