chr9-21971024-C-A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1PM5PP3BS2_Supporting

The NM_000077.5(CDKN2A):​c.335G>T​(p.Arg112Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000436 in 1,606,934 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R112C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

CDKN2A
NM_000077.5 missense

Scores

5
7
6

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.412
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]

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 17 uncertain in NM_000077.5
PM5
Other missense variant is known to change same aminoacid residue: Variant chr9-21971025-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 233484.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.839
BS2
High AC in GnomAdExome4 at 6 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CDKN2ANM_000077.5 linkc.335G>T p.Arg112Leu missense_variant Exon 2 of 3 ENST00000304494.10 NP_000068.1 P42771-1K7PML8
CDKN2ANM_058195.4 linkc.378G>T p.Pro126Pro synonymous_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.335G>T p.Arg112Leu missense_variant Exon 2 of 3 1 NM_000077.5 ENSP00000307101.5 P42771-1
CDKN2AENST00000579755.2 linkc.378G>T p.Pro126Pro synonymous_variant Exon 2 of 3 1 NM_058195.4 ENSP00000462950.1 Q8N726-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152234
Hom.:
0
Cov.:
32
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:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000841
AC:
2
AN:
237904
AF XY:
0.00000768
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000564
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000412
AC:
6
AN:
1454582
Hom.:
0
Cov.:
31
AF XY:
0.00000414
AC XY:
3
AN XY:
723860
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33444
American (AMR)
AF:
0.00
AC:
0
AN:
44652
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26078
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39676
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86136
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47660
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5192
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111510
Other (OTH)
AF:
0.00
AC:
0
AN:
60234
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
1
2
2
3
4
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
AF:
0.00000656
AC:
1
AN:
152352
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74502
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41586
American (AMR)
AF:
0.00
AC:
0
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
292
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
ExAC
AF:
0.0000166
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1
Jun 29, 2018
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R112L variant (also known as c.335G>T), located in coding exon 2 of the CDKN2A gene, results from a G to T substitution at nucleotide position 335. The arginine at codon 112 is replaced by leucine, 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 deleterious 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 28, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 112 of the CDKN2A (p16INK4a) protein (p.Arg112Leu). This variant is present in population databases (rs587782797, gnomAD 0.006%). 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: 823661). 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25"). This variant disrupts the p.Arg112 amino acid residue in CDKN2A (p16INK4a). Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10398427, 11518711, 12606942, 16307646, 20340136, 21462282). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.57
BayesDel_addAF
Pathogenic
0.29
D
BayesDel_noAF
Pathogenic
0.36
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.47
T;T;.;.;.;.;T;.
Eigen
Uncertain
0.51
Eigen_PC
Uncertain
0.54
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.83
T;T;.;T;.;T;T;T
M_CAP
Pathogenic
0.63
D
MetaRNN
Pathogenic
0.84
D;D;D;D;D;D;D;D
MetaSVM
Benign
-0.60
T
PhyloP100
0.41
PrimateAI
Benign
0.41
T
PROVEAN
Uncertain
-4.3
D;.;.;D;.;.;.;.
REVEL
Uncertain
0.46
Sift
Benign
0.14
T;.;.;T;.;.;.;.
Sift4G
Benign
0.19
T;T;T;T;T;T;T;T
Polyphen
1.0
D;.;.;.;.;.;.;.
Vest4
0.68
MutPred
0.55
Loss of MoRF binding (P = 0.0133);Loss of MoRF binding (P = 0.0133);.;Loss of MoRF binding (P = 0.0133);.;.;.;.;
MVP
0.99
MPC
1.0
ClinPred
0.88
D
GERP RS
5.9
PromoterAI
0.053
Neutral
Varity_R
0.48
gMVP
0.72
Mutation Taster
=1/99
disease causing

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

LitVar

Below is the list of publications found by LitVar for variant 9:21971024 C>A . It may be empty.

Other links and lift over

dbSNP: rs587782797; hg19: chr9-21971023; API