9-21970953-C-T

Variant names:

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>A(p.Gly136Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,612,104 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. G136D) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

CDKN2A
NM_000077.5 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: -0.0230

Publications

5 publications found

Variant links:

COSMIC-nc: COSV58696417

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

CDKN2A links:

ENSG00000264545 (HGNC:):

ENSG00000264545 links:

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=0.072701156).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN2A	NM_000077.5 link	c.406G>A	p.Gly136Ser	missense_variant	Exon 2 of 3	ENST00000304494.10	NP_000068.1
CDKN2A	NM_058195.4 link	c.*50G>A		3_prime_UTR_variant	Exon 2 of 3	ENST00000579755.2	NP_478102.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKN2A	ENST00000304494.10 link	c.406G>A	p.Gly136Ser	missense_variant	Exon 2 of 3	1	NM_000077.5	ENSP00000307101.5
CDKN2A	ENST00000579755.2 link	c.*50G>A		3_prime_UTR_variant	Exon 2 of 3	1	NM_058195.4	ENSP00000462950.1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152232

Hom.:

Cov.:

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:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000122

AC:

AN:

245668

AF XY:

0.00000748

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000553

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000181

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1459756

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726268

show subpopulations

African (AFR)

AF:

0.0000598

AC:

AN:

33462

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86224

European-Finnish (FIN)

AF:

0.00

AC:

AN:

51920

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5280

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111998

Other (OTH)

AF:

0.00

AC:

AN:

60314

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.463

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

AF:

0.00000656

AC:

AN:

152348

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74504

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41592

American (AMR)

AF:

0.00

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000193

AC:

AN:

5178

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

ExAC

AF:

0.0000165

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Apr 02, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as a pathogenic or benign germline variant to our knowledge; This variant is associated with the following publications: (PMID: 19690981) -

Hereditary cancer-predisposing syndrome

Uncertain:1

Jul 10, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.G136S variant (also known as c.406G>A), located in coding exon 2 of the CDKN2A gene, results from a G to A substitution at nucleotide position 406. The glycine at codon 136 is replaced by serine, an amino acid with similar 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

Nov 20, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 136 of the CDKN2A (p16INK4a) protein (p.Gly136Ser). This variant is present in population databases (rs777840257, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with CDKN2A (p16INK4a)-related conditions. ClinVar contains an entry for this variant (Variation ID: 483342). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The serine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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

Benign

0.098

BayesDel_addAF

Benign

-0.000083

BayesDel_noAF

Benign

-0.22

CADD

Benign

8.8

(source)

DANN

Benign

0.88

DEOGEN2

Benign

0.055

T;.;.;.;.;T;.

Eigen

Benign

-1.0

Eigen_PC

Benign

-0.97

FATHMM_MKL

Benign

0.045

LIST_S2

Benign

0.75

T;.;T;.;T;T;T

M_CAP

Uncertain

0.12

MetaRNN

Benign

0.073

T;T;T;T;T;T;T

MetaSVM

Benign

-0.49

PhyloP100

-0.023

PrimateAI

Benign

0.34

PROVEAN

Benign

-0.30

N;.;N;.;.;.;.

REVEL

Benign

0.26

Sift

Benign

0.73

T;.;T;.;.;.;.

Sift4G

Benign

0.88

T;T;T;T;T;T;T

Polyphen

0.085

B;.;.;.;.;.;.

Vest4

0.15

MutPred

0.28

Gain of glycosylation at G136 (P = 0.0031);.;Gain of glycosylation at G136 (P = 0.0031);.;.;.;.;

MVP

0.88

MPC

0.59

ClinPred

0.059

GERP RS

1.7

PromoterAI

-0.061

Neutral

(source)

Varity_R

0.032

gMVP

0.47

Mutation Taster

=8/92

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over