NM_004064.5:c.492C>A

Variant names:

• chr12-12718841-C-A
• rs762810555
• NM_004064.5:c.492C>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_004064.5(CDKN1B):​c.492C>A​(p.Asn164Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,860 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N164S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: CDKN1B NM_004064.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.29
• Publications: 0 publications found

Genes affected

CDKN1B (HGNC:1785): (cyclin dependent kinase inhibitor 1B) This gene encodes a cyclin-dependent kinase inhibitor, which shares a limited similarity with CDK inhibitor CDKN1A/p21. The encoded protein binds to and prevents the activation of cyclin E-CDK2 or cyclin D-CDK4 complexes, and thus controls the cell cycle progression at G1. The degradation of this protein, which is triggered by its CDK dependent phosphorylation and subsequent ubiquitination by SCF complexes, is required for the cellular transition from quiescence to the proliferative state. Mutations in this gene are associated with multiple endocrine neoplasia type IV (MEN4). [provided by RefSeq, Apr 2014]

CDKN1B Gene-Disease associations (from GenCC):

• multiple endocrine neoplasia type 4

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet, ClinGen
• multiple endocrine neoplasia

  Inheritance: AD Classification: STRONG Submitted by: G2P
• hereditary nonpolyposis colon cancer

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.24936685).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN1B	NM_004064.5	c.492C>A	p.Asn164Lys	missense_variant	Exon 2 of 3	ENST00000228872.9	NP_004055.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKN1B	ENST00000228872.9	c.492C>A	p.Asn164Lys	missense_variant	Exon 2 of 3	1	NM_004064.5	ENSP00000228872.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461860 Hom.: 0 Cov.: 31 AF XY: 0.00000963 AC XY: 7 AN XY: 727230

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000899 AC: 10 AN: 1111986

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Multiple endocrine neoplasia type 4 Uncertain:1

Apr 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 164 of the CDKN1B protein (p.Asn164Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CDKN1B-related conditions. ClinVar contains an entry for this variant (Variation ID: 1467671). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Mar 26, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.N164K variant (also known as c.492C>A), located in coding exon 2 of the CDKN1B gene, results from a C to A substitution at nucleotide position 492. The asparagine at codon 164 is replaced by lysine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.50
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.38
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.37	T;.
Eigen	Uncertain	0.22
Eigen_PC	Uncertain	0.22
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Benign	0.80	T;T
M_CAP	Benign	0.059	D
MetaRNN	Benign	0.25	T;T
MetaSVM	Benign	-0.66	T
MutationAssessor	Benign	0.97	L;.
PhyloP100		2.3
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-1.3	N;N
REVEL	Benign	0.17
Sift	Benign	0.14	T;T
Sift4G	Benign	0.52	T;T
Polyphen		0.99	D;.
Vest4		0.54
MutPred		0.23		Gain of ubiquitination at N164 (P = 0.0029);.;
MVP		0.71
MPC		0.34
ClinPred		0.95	D
GERP RS		4.2
Varity_R		0.15
gMVP		0.16
Mutation Taster		=68/32	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs762810555; hg19: chr12-12871775;