12-12717993-A-G

Variant names:

• chr12-12717993-A-G
• rs760647541
• NM_004064.5:c.154A>G

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2 BP4_Moderate BS2

The NM_004064.5(CDKN1B):​c.154A>G​(p.Met52Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: CDKN1B NM_004064.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.56

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]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2145651).
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN1B	NM_004064.5	c.154A>G	p.Met52Val	missense_variant	Exon 1 of 3	ENST00000228872.9	NP_004055.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKN1B	ENST00000228872.9	c.154A>G	p.Met52Val	missense_variant	Exon 1 of 3	1	NM_004064.5	ENSP00000228872.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461892 Hom.: 0 Cov.: 51 AF XY: 0.00000275 AC XY: 2 AN XY: 727246

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Nov 01, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 52 of the CDKN1B protein (p.Met52Val). 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: 972320). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15"). 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

Jun 11, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.M52V variant (also known as c.154A>G), located in coding exon 1 of the CDKN1B gene, results from an A to G substitution at nucleotide position 154. The methionine at codon 52 is replaced by valine, an amino acid with highly 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	Benign	0.18
BayesDel_addAF	Benign	0.0098	T
BayesDel_noAF	Benign	-0.22
CADD	Benign	21
DANN	Uncertain	0.98
DEOGEN2	Benign	0.13	T;T;.
Eigen	Benign	-0.082
Eigen_PC	Benign	0.017
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.79	T;T;T
M_CAP	Benign	0.061	D
MetaRNN	Benign	0.21	T;T;T
MetaSVM	Benign	-0.51	T
MutationAssessor	Benign	1.2	L;.;.
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-0.65	N;N;N
REVEL	Benign	0.24
Sift	Uncertain	0.012	D;T;T
Sift4G	Benign	0.063	T;D;T
Polyphen		0.32	B;.;.
Vest4		0.50
MutPred		0.50		Loss of ubiquitination at K47 (P = 0.073);Loss of ubiquitination at K47 (P = 0.073);.;
MVP		0.69
MPC		0.10
ClinPred		0.57	D
GERP RS		2.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.65
gMVP		0.50

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

LitVar

Other links and lift over

dbSNP: rs760647541; hg19: chr12-12870927;