12-12717943-C-G

Variant names:

• chr12-12717943-C-G
• rs375297371
• NM_004064.5:c.104C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_004064.5(CDKN1B):​c.104C>G​(p.Pro35Arg) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. P35L) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CDKN1B NM_004064.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.54
• 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_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 28 uncertain in NM_004064.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.915

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN1B	NM_004064.5	c.104C>G	p.Pro35Arg	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.104C>G	p.Pro35Arg	missense_variant	Exon 1 of 3	1	NM_004064.5	ENSP00000228872.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 50

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

Feb 10, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P35R variant (also known as c.104C>G), located in coding exon 1 of the CDKN1B gene, results from a C to G substitution at nucleotide position 104. The proline at codon 35 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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	0.39
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.40	T;T;.
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.92	D;D;D
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Uncertain	2.3	M;.;.
PhyloP100		4.5
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-6.8	D;D;D
REVEL	Pathogenic	0.65
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.0030	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.66
MutPred		0.80		Gain of MoRF binding (P = 0.0673);Gain of MoRF binding (P = 0.0673);.;
MVP		0.71
MPC		0.34
ClinPred		0.99	D
GERP RS		4.3
PromoterAI		-0.018	Neutral
Varity_R		0.90
gMVP		0.50
Mutation Taster		=75/25	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: rs375297371; hg19: chr12-12870877;