9-21971018-G-C

Variant names:

• chr9-21971018-G-C
• rs121913386
• NM_000077.5:c.341C>G

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_000077.5(CDKN2A):​c.341C>G​(p.Pro114Arg) variant causes a missense change involving the alteration of a conserved nucleotide. 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P114L) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CDKN2A NM_000077.5 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.18
• Publications: 0 publications found

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

ENSG00000264545 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 44 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 chr9-21971018-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 77637.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985
• PP5: Variant 9-21971018-G-C is Pathogenic according to our data. Variant chr9-21971018-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2449062.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000077.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CDKN2A	NM_000077.5	MANE Select	c.341C>G	p.Pro114Arg	missense	Exon 2 of 3	NP_000068.1
	CDKN2A	NM_058195.4	MANE Plus Clinical	c.384C>G	p.Ala128Ala	synonymous	Exon 2 of 3	NP_478102.2
	CDKN2A	NM_001195132.2		c.341C>G	p.Pro114Arg	missense	Exon 2 of 4	NP_001182061.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CDKN2A	ENST00000304494.10	TSL:1 MANE Select	c.341C>G	p.Pro114Arg	missense	Exon 2 of 3	ENSP00000307101.5
	CDKN2A	ENST00000498124.1	TSL:1	c.341C>G	p.Pro114Arg	missense	Exon 2 of 4	ENSP00000418915.1
	CDKN2A	ENST00000579755.2	TSL:1 MANE Plus Clinical	c.384C>G	p.Ala128Ala	synonymous	Exon 2 of 3	ENSP00000462950.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Jan 23, 2023

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P114R variant (also known as c.341C>G), located in coding exon 2 of the CDKN2A gene, results from a C to G substitution at nucleotide position 341. The proline at codon 114 is replaced by arginine, an amino acid with dissimilar properties. This alteration has been observed in at least one individual with a personal and/or family history that is consistent with CDKN2A-related disease (Ambry internal data). Another alteration at the same codon, p.P114L (c.341C>T), has been detected in multiple individuals who have a personal or family history that is consistent with CDKN2A-associated disease (Ambry internal data; Fargnoli MC et al. J. Invest. Dermatol., 1998 Dec;111:1202-6; Miller PJ et al. Hum. Mutat., 2011 Aug;32:900-11). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.59	D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.76	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.18	D
PhyloP100		9.2
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-8.4	D
REVEL	Pathogenic	0.88
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.87		Gain of MoRF binding (P = 0.007)
MVP		1.0
MPC		1.3
ClinPred		1.0	D
GERP RS		5.9
PromoterAI		-0.010	Neutral
Varity_R		0.93
gMVP		0.86
Mutation Taster		=0/100	disease causing

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

Other links and lift over

dbSNP: rs121913386; hg19: chr9-21971017; COSMIC: COSV58692178; COSMIC: COSV58692178;