rs1554937699

Variant names:

• chr11-2884669-C-T
• rs1554937699
• NM_001122630.2:c.787+1G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_001122630.2(CDKN1C):​c.787+1G>A variant causes a splice donor, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CDKN1C NM_001122630.2 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.666
• 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: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDKN1C	NM_001122630.2	c.787+1G>A		splice_donor_variant, intron_variant	Intron 2 of 3	ENST00000440480.8	NP_001116102.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDKN1C	ENST00000440480.8	c.787+1G>A		splice_donor_variant, intron_variant	Intron 2 of 3	1	NM_001122630.2	ENSP00000411257.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1229544 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 605630

African (AFR) AF: 0.00 AC: 0 AN: 25076

American (AMR) AF: 0.00 AC: 0 AN: 21206

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 17576

East Asian (EAS) AF: 0.00 AC: 0 AN: 28576

South Asian (SAS) AF: 0.00 AC: 0 AN: 59066

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 29860

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3774

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 995762

Other (OTH) AF: 0.00 AC: 0 AN: 48648

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

Jul 14, 2023

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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 454035). This variant has not been reported in the literature in individuals affected with CDKN1C-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 1 of the CDKN1C gene. While this variant is not anticipated to result in nonsense mediated decay, it likely alters RNA splicing and results in a disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Benign	-0.16
CADD	Pathogenic	28
DANN	Uncertain	0.99
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.34
FATHMM_MKL	Benign	0.48	N
PhyloP100		0.67
GERP RS		0.98
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Mutation Taster		=70/30	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.97		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1554937699; hg19: chr11-2905899;