9-21994203-C-T

Variant names:

• chr9-21994203-C-T
• rs776615460
• NM_058195.4:c.129G>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_058195.4(CDKN2A):​c.129G>A​(p.Val43Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,454,414 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. V43V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CDKN2A NM_058195.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.807
• 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]

CDKN2B-AS1 (HGNC:34341): (CDKN2B antisense RNA 1) This gene is located within the CDKN2B-CDKN2A gene cluster at chromosome 9p21. The gene product is a functional RNA molecule that interacts with polycomb repressive complex-1 (PRC1) and -2 (PRC2), leading to epigenetic silencing of other genes in this cluster. This region is a significant genetic susceptibility locus for cardiovascular disease, and has also been linked to a number of other pathologies, including several cancers, intracranial aneurysm, type-2 diabetes, periodontitis, Alzheimer's disease, endometriosis, frailty in the elderly, and glaucoma. Multiple alternatively processed transcript variants have been detected, some of which may take the form of circular RNA molecules (PMID:21151960). [provided by RefSeq, May 2014]

ENSG00000264545 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.34).
• BP7: Synonymous conserved (PhyloP=0.807 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN2A	NM_058195.4	c.129G>A	p.Val43Val	synonymous_variant	Exon 1 of 3	ENST00000579755.2	NP_478102.2
CDKN2A	NM_001363763.2	c.-4+618G>A		intron_variant	Intron 1 of 2		NP_001350692.1
CDKN2A	XM_047422597.1	c.-4+344G>A		intron_variant	Intron 1 of 2		XP_047278553.1
LOC124902130	XR_007061436.1	n.-175G>A		upstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKN2A	ENST00000579755.2	c.129G>A	p.Val43Val	synonymous_variant	Exon 1 of 3	1	NM_058195.4	ENSP00000462950.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000426 AC: 1 AN: 235010 AF XY: 0.00000769

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1454414 Hom.: 0 Cov.: 32 AF XY: 0.00000414 AC XY: 3 AN XY: 723896

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44692

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26106

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86224

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 46434

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5738

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111806

Other (OTH) AF: 0.00 AC: 0 AN: 60248

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.34
CADD	Benign	12
DANN	Benign	0.96
PhyloP100		0.81
PromoterAI		-0.076	Neutral

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

Other links and lift over

dbSNP: rs776615460; hg19: chr9-21994202;