12-12717859-C-T

Variant names:

• chr12-12717859-C-T
• rs368157535
• NM_004064.5:c.20C>T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_004064.5(CDKN1B):​c.20C>T​(p.Ser7Phe) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,272 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. S7C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CDKN1B NM_004064.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.17
• 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: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.827

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN1B	NM_004064.5	c.20C>T	p.Ser7Phe	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.20C>T	p.Ser7Phe	missense_variant	Exon 1 of 3	1	NM_004064.5	ENSP00000228872.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461272 Hom.: 0 Cov.: 50 AF XY: 0.00 AC XY: 0 AN XY: 726944

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33470

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: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53084

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5538

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60366

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Sep 26, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.S7F variant (also known as c.20C>T), located in coding exon 1 of the CDKN1B gene, results from a C to T substitution at nucleotide position 20. The serine at codon 7 is replaced by phenylalanine, an amino acid with highly dissimilar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.73	D;T
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.83	D;D
MetaSVM	Uncertain	0.67	D
MutationAssessor	Uncertain	2.1	M;.
PhyloP100		7.2
PrimateAI	Uncertain	0.75	T
PROVEAN	Uncertain	-3.0	D;D
REVEL	Uncertain	0.62
Sift	Uncertain	0.028	D;D
Sift4G	Pathogenic	0.0	D;T
Polyphen		1.0	D;.
Vest4		0.95
MutPred		0.25		Loss of phosphorylation at S7 (P = 0.0175);Loss of phosphorylation at S7 (P = 0.0175);
MVP		0.82
MPC		0.16
ClinPred		0.99	D
GERP RS		4.4
PromoterAI		0.0065	Neutral
Varity_R		0.34
gMVP		0.73
Mutation Taster		=51/49	polymorphism

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: rs368157535; hg19: chr12-12870793;