NM_058195.4:c.145C>T

Variant names:

• chr9-21994187-G-A
• rs1554659187
• NM_058195.4:c.145C>T

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 2P and 11B. PM2 BP4_Moderate BP6_Very_Strong BP7

The NM_058195.4(CDKN2A):​c.145C>T​(p.Leu49Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000275 in 1,453,536 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. L49L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: CDKN2A NM_058195.4 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: 0.646
• 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: Benign. The variant received -9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.38).
• BP6: Variant 9-21994187-G-A is Benign according to our data. Variant chr9-21994187-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 532303.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.646 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_058195.4. 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_058195.4	MANE Plus Clinical	c.145C>T	p.Leu49Leu	synonymous	Exon 1 of 3	NP_478102.2
	CDKN2A	NM_001363763.2		c.-4+634C>T		intron	N/A	NP_001350692.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CDKN2A	ENST00000579755.2	TSL:1 MANE Plus Clinical	c.145C>T	p.Leu49Leu	synonymous	Exon 1 of 3	ENSP00000462950.1
	CDKN2A	ENST00000530628.2	TSL:5	c.145C>T	p.Leu49Leu	synonymous	Exon 1 of 3	ENSP00000432664.2
	CDKN2B-AS1	ENST00000468603.7	TSL:5	n.49G>A		non_coding_transcript_exon	Exon 1 of 4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000275 AC: 4 AN: 1453536 Hom.: 0 Cov.: 32 AF XY: 0.00000415 AC XY: 3 AN XY: 723482

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44698

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 45428

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5748

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111872

Other (OTH) AF: 0.00 AC: 0 AN: 60266

GnomAD4 genome Cov.: 31

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Melanoma-pancreatic cancer syndrome Benign:1

Aug 12, 2025

Myriad Genetics, Inc.

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered benign. This variant is a silent/synonymous amino acid change and it is not expected to impact splicing.

Hereditary cancer-predisposing syndrome Benign:1

Jan 10, 2022

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Familial melanoma Benign:1

Aug 22, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.38
CADD	Benign	14
DANN	Benign	0.96
PhyloP100		0.65
PromoterAI		0.087	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs1554659187; hg19: chr9-21994186;