chr9-21971034-C-T

Position:

• chr9-21971034-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000077.5(CDKN2A):​c.325G>A​(p.Ala109Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CDKN2A NM_000077.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.141

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 Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a chain Cyclin-dependent kinase inhibitor 2A (size 155) in uniprot entity CDN2A_HUMAN there are 42 pathogenic changes around while only 12 benign (78%) in NM_000077.5
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.26101148).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDKN2A	NM_000077.5	c.325G>A	p.Ala109Thr	missense_variant	2/3	ENST00000304494.10	NP_000068.1
CDKN2A	NM_058195.4	c.368G>A	p.Cys123Tyr	missense_variant	2/3	ENST00000579755.2	NP_478102.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDKN2A	ENST00000304494.10	c.325G>A	p.Ala109Thr	missense_variant	2/3	1	NM_000077.5	ENSP00000307101	P2
CDKN2A	ENST00000579755.2	c.368G>A	p.Cys123Tyr	missense_variant	2/3	1	NM_058195.4	ENSP00000462950

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1454012 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 723582

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

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.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Benign	-0.18
CADD	Benign	19
DANN	Benign	0.94
DEOGEN2	Benign	0.12	T;T;.;.;.;.;T;.
Eigen	Benign	-0.15
Eigen_PC	Benign	-0.14
FATHMM_MKL	Benign	0.13	N
LIST_S2	Benign	0.69	T;T;.;T;.;T;T;T
M_CAP	Uncertain	0.12	D
MetaRNN	Benign	0.26	T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.82	T
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-1.7	N;.;.;N;.;.;.;.
REVEL	Uncertain	0.45
Sift	Benign	0.39	T;.;.;T;.;.;.;.
Sift4G	Benign	0.35	T;T;T;T;T;T;T;T
Polyphen		0.28	B;.;.;.;.;.;.;.
Vest4		0.18
MutPred		0.36		Gain of phosphorylation at A109 (P = 0.0304);Gain of phosphorylation at A109 (P = 0.0304);.;Gain of phosphorylation at A109 (P = 0.0304);.;.;.;.;
MVP		0.98
MPC		0.41
ClinPred		0.28	T
GERP RS		3.9
Varity_R		0.10
gMVP		0.56

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: chr9-21971033; COSMIC: COSV58702696; COSMIC: COSV58702696;