rs758389471

chr9-21971160-C-Achr9-21971160-C-Gchr9-21971160-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000077.5(CDKN2A):c.199G>T(p.Gly67Cys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. G67R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CDKN2A NM_000077.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.57

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 16 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 chr9-21971160-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 216272.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.961

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CDKN2A	NM_000077.5	c.199G>T	p.Gly67Cys	missense_variant	2/3	ENST00000304494.10
CDKN2A	NM_058195.4	c.242G>T	p.Arg81Leu	missense_variant	2/3	ENST00000579755.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CDKN2A	ENST00000304494.10	c.199G>T	p.Gly67Cys	missense_variant	2/3	1	NM_000077.5	P2
CDKN2A	ENST00000579755.2	c.242G>T	p.Arg81Leu	missense_variant	2/3	1	NM_058195.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 26, 2023

The p.G67C variant (also known as c.199G>T), located in coding exon 2 of the CDKN2A gene, results from a G to T substitution at nucleotide position 199. The glycine at codon 67 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is highly 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.79
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Uncertain	-0.020
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.56	D;T;.;.;.;.;T;.
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.98	D;D;.;D;.;D;D;D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.044	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.68	T
PROVEAN	Pathogenic	-8.6	D;.;.;D;.;.;.;.
REVEL	Pathogenic	0.86
Sift	Pathogenic	0.0	D;.;.;D;.;.;.;.
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D;D
Polyphen		1.0	D;.;.;.;.;.;.;.
Vest4		0.56
MutPred		0.85		Loss of disorder (P = 0.0798);Loss of disorder (P = 0.0798);.;Loss of disorder (P = 0.0798);.;.;.;.;
MVP		1.0
MPC		1.3
ClinPred		0.98	D
GERP RS		5.8
Varity_R		0.61
gMVP		0.96

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr9-21971159; COSMIC: COSV58712216; COSMIC: COSV58712216;