12-12718110-C-G

Position:

• chr12-12718110-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_004064.5(CDKN1B):​c.271C>G​(p.Pro91Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,852 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: 0.0000021 (0 hom.)
• Consequence: CDKN1B NM_004064.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.63

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.14237174).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDKN1B	NM_004064.5	c.271C>G	p.Pro91Ala	missense_variant	1/3	ENST00000228872.9	NP_004055.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDKN1B	ENST00000228872.9	c.271C>G	p.Pro91Ala	missense_variant	1/3	1	NM_004064.5	ENSP00000228872.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250408 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135806

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000164

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461852 Hom.: 0 Cov.: 51 AF XY: 0.00000138 AC XY: 1 AN XY: 727224

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: 0.00

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 13, 2023

This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 91 of the CDKN1B protein (p.Pro91Ala). This variant is present in population databases (rs769828807, 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: 1035960). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The alanine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 02, 2022

The p.P91A variant (also known as c.271C>G), located in coding exon 1 of the CDKN1B gene, results from a C to G substitution at nucleotide position 271. The proline at codon 91 is replaced by alanine, an amino acid with highly similar properties. This amino acid position is highly conserved through mammals but not in all available vertebrate species. 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	0.076
BayesDel_addAF	Benign	-0.021	T
BayesDel_noAF	Benign	-0.27
CADD	Benign	20
DANN	Uncertain	0.98
DEOGEN2	Benign	0.27	T;T
Eigen	Benign	-0.11
Eigen_PC	Benign	0.0062
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.76	T;T
M_CAP	Benign	0.048	D
MetaRNN	Benign	0.14	T;T
MetaSVM	Uncertain	-0.17	T
MutationAssessor	Benign	1.3	L;.
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.95	N;N
REVEL	Benign	0.19
Sift	Benign	0.097	T;T
Sift4G	Benign	0.13	T;T
Polyphen		0.011	B;.
Vest4		0.13
MutPred		0.32		Loss of catalytic residue at P91 (P = 0.0075);Loss of catalytic residue at P91 (P = 0.0075);
MVP		0.54
MPC		0.068
ClinPred		0.25	T
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.19
gMVP		0.32

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: rs769828807; hg19: chr12-12871044;