NM_018451.5:c.3217-2A>G

Variant names:

• chr13-24889402-T-C
• rs1555295400
• NM_018451.5:c.3217-2A>G

Variant summary

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

The NM_018451.5(CPAP):​c.3217-2A>G variant causes a splice acceptor, 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: 32)
• Consequence: CPAP NM_018451.5 splice_acceptor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.76
• Publications: 0 publications found

Genes affected

CPAP (HGNC:17272): (centromere protein J) This gene encodes a protein that belongs to the centromere protein family. During cell division, this protein plays a structural role in the maintenance of centrosome integrity and normal spindle morphology, and it is involved in microtubule disassembly at the centrosome. This protein can function as a transcriptional coactivator in the Stat5 signaling pathway, and also as a coactivator of NF-kappaB-mediated transcription, likely via its interaction with the coactivator p300/CREB-binding protein. Mutations in this gene are associated with primary autosomal recessive microcephaly, a disorder characterized by severely reduced brain size and cognitive disability. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Apr 2012]

CPAP Gene-Disease associations (from GenCC):

• microcephaly 6 with or without short stature

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• microcephaly 6, primary, autosomal recessive

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• autosomal recessive primary microcephaly

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Seckel syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

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, Cryptic splice site detected, with MaxEntScore 5.5, offset of 26, new splice context is: tctgttcgatttcaaaacAGtca. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_018451.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CPAP	NM_018451.5	MANE Select	c.3217-2A>G		splice_acceptor intron	N/A	NP_060921.3
	CPAP	NR_047594.2		n.3384-2A>G		splice_acceptor intron	N/A
	CPAP	NR_047595.2		n.3383+3241A>G		intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CENPJ	ENST00000381884.9	TSL:1 MANE Select	c.3217-2A>G		splice_acceptor intron	N/A	ENSP00000371308.4
	CENPJ	ENST00000418179.1	TSL:1	c.460-2A>G		splice_acceptor intron	N/A	ENSP00000399334.1
	CENPJ	ENST00000616936.4	TSL:1	n.3216+3241A>G		intron	N/A	ENSP00000477511.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	-0.030
CADD	Pathogenic	26
DANN	Uncertain	0.98
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Benign	0.70	D
PhyloP100		2.8
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=5/95	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.90		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.90		Position offset: -2

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

Other links and lift over

dbSNP: rs1555295400; hg19: chr13-25463540;