chr9-21971007-C-A

Position:

• chr9-21971007-C-A

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.352G>T​(p.Ala118Ser) 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A118T) has been classified as Likely pathogenic.

• 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: 7.27

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 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
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-21971007-C-T is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.961

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDKN2A	NM_000077.5	c.352G>T	p.Ala118Ser	missense_variant	2/3	ENST00000304494.10	NP_000068.1
CDKN2A	NM_058195.4	c.395G>T	p.Gly132Val	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.352G>T	p.Ala118Ser	missense_variant	2/3	1	NM_000077.5	ENSP00000307101	P2
CDKN2A	ENST00000579755.2	c.395G>T	p.Gly132Val	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: 1456556 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 724842

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	Uncertain	0.42
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.44	T;T;.;.;.;.;T;.
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;D;.;D;.;D;D;D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.24	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Uncertain	-2.7	D;.;.;D;.;.;.;.
REVEL	Pathogenic	0.75
Sift	Uncertain	0.019	D;.;.;D;.;.;.;.
Sift4G	Uncertain	0.030	D;D;T;D;T;T;D;T
Polyphen		0.99	D;.;.;.;.;.;.;.
Vest4		0.78
MutPred		0.81		Gain of disorder (P = 0.0508);Gain of disorder (P = 0.0508);.;Gain of disorder (P = 0.0508);.;.;.;.;
MVP		0.97
MPC		1.2
ClinPred		0.97	D
GERP RS		5.9
Varity_R		0.36
gMVP		0.68

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr9-21971006;