NM_001122630.2:c.827C>G

Variant names:

• chr11-2884095-G-C
• rs928007699
• NM_001122630.2:c.827C>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_001122630.2(CDKN1C):​c.827C>G​(p.Ser276Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 12/18 in silico tools predict 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. S276L) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CDKN1C NM_001122630.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.47
• Publications: 0 publications found

Genes affected

CDKN1C (HGNC:1786): (cyclin dependent kinase inhibitor 1C) This gene is imprinted, with preferential expression of the maternal allele. The encoded protein is a tight-binding, strong inhibitor of several G1 cyclin/Cdk complexes and a negative regulator of cell proliferation. Mutations in this gene are implicated in sporadic cancers and Beckwith-Wiedemann syndorome, suggesting that this gene is a tumor suppressor candidate. Three transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq, Oct 2010]

CDKN1C Gene-Disease associations (from GenCC):

• Beckwith-Wiedemann syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• IMAGe syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Illumina, G2P, Ambry Genetics
• rhabdomyosarcoma

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• Beckwith-Wiedemann syndrome due to CDKN1C mutation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• intrauterine growth restriction-short stature-early adult-onset diabetes syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Silver-Russell syndrome

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 22 uncertain in NM_001122630.2
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22385353).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN1C	NM_001122630.2	c.827C>G	p.Ser276Trp	missense_variant	Exon 3 of 4	ENST00000440480.8	NP_001116102.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKN1C	ENST00000440480.8	c.827C>G	p.Ser276Trp	missense_variant	Exon 3 of 4	1	NM_001122630.2	ENSP00000411257.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Beckwith-Wiedemann syndrome Uncertain:1

Mar 23, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. This variant has not been reported in the literature in individuals with CDKN1C-related disease. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This sequence change replaces serine with tryptophan at codon 287 of the CDKN1C protein (p.Ser287Trp). The serine residue is weakly conserved and there is a large physicochemical difference between serine and tryptophan. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.51
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Benign	-0.20
CADD	Benign	22
DANN	Benign	0.67
DEOGEN2	Benign	0.012	T;.
Eigen	Benign	-0.69
Eigen_PC	Benign	-0.77
FATHMM_MKL	Benign	0.10	N
LIST_S2	Benign	0.47	.;T
M_CAP	Pathogenic	0.89	D
MetaRNN	Benign	0.22	T;T
MetaSVM	Benign	-0.54	T
PhyloP100		2.5
PROVEAN	Benign	-1.1	N;.
REVEL	Benign	0.16
Sift	Benign	0.042	D;.
Sift4G	Benign	0.13	T;.
Polyphen		0.97	D;.
Vest4		0.25
MutPred		0.22		Loss of solvent accessibility (P = 0.0329);Loss of solvent accessibility (P = 0.0329);
MVP		0.54
ClinPred		0.32	T
GERP RS		2.2
Varity_R		0.11
Mutation Taster		=94/6	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs928007699; hg19: chr11-2905325;