3-33114550-C-T

Position:

chr3-33114550-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_StrongPM2

The ENST00000320954.11(CRTAP):c.471+2C>T variant causes a splice donor change. The variant allele was found at a frequency of 0.00000822 in 1,580,606 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 34)

Exomes 𝑓: 0.0000084 ( 0 hom. )

Consequence

CRTAP
ENST00000320954.11 splice_donor

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.71

Variant links:

Genes affected

CRTAP (HGNC:2379): (cartilage associated protein) The protein encoded by this gene is similar to the chicken and mouse CRTAP genes. The encoded protein is a scaffolding protein that may influence the activity of at least one member of the cytohesin/ARNO family in response to specific cellular stimuli. Defects in this gene are associated with osteogenesis imperfecta, a connective tissue disorder characterized by bone fragility and low bone mass. [provided by RefSeq, Jul 2008]

CRTAP links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.44278607 fraction of the gene. Cryptic splice site detected, with MaxEntScore 11, offset of 0 (no position change), new splice context is: aagGTaagt. Cryptic site results in inframe 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;

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	MANE	Protein
CRTAP	NM_006371.5 linkuse as main transcript	c.471+2C>T	splice_donor_variant	ENST00000320954.11	NP_006362.1
CRTAP	NM_001393363.1 linkuse as main transcript	c.471+2C>T	splice_donor_variant		NP_001380292.1
CRTAP	NM_001393364.1 linkuse as main transcript	c.471+2C>T	splice_donor_variant		NP_001380293.1
CRTAP	NM_001393365.1 linkuse as main transcript	c.471+2C>T	splice_donor_variant		NP_001380294.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CRTAP	ENST00000320954.11 linkuse as main transcript	c.471+2C>T		splice_donor_variant		1	NM_006371.5	ENSP00000323696	P1
CRTAP	ENST00000449224.1 linkuse as main transcript	c.471+2C>T		splice_donor_variant		2		ENSP00000409997

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000840

AC:

AN:

1428398

Hom.:

Cov.:

AF XY:

0.00000848

AC XY:

AN XY:

707764

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000260

Gnomad4 SAS exome

AF:

0.0000122

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000821

Gnomad4 OTH exome

AF:

0.0000170

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74356

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Osteogenesis imperfecta type 7

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 01, 2021

This sequence change falls in intron 1 of the CRTAP gene. It does not directly change the encoded amino acid sequence of the CRTAP protein. It affects a nucleotide within the consensus splice site of the intron. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. This variant has not been reported in the literature in individuals affected with CRTAP-related conditions. 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 create or strengthen a splice site. This variant disrupts the c.471+2C nucleotide in the CRTAP gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 18996919, 19550437). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Benign

-0.16

CADD

Pathogenic

DANN

Benign

0.93

Eigen

Pathogenic

0.68

Eigen_PC

Uncertain

0.44

FATHMM_MKL

Benign

0.50

MutationTaster

Benign

1.0

D;D

GERP RS

0.99

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over