3-33114093-CG-CGGG

Variant names:

• chr3-33114093-C-CGG
• rs137853936
• NM_006371.5:c.21_22dupGG

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_006371.5(CRTAP):​c.21_22dupGG​(p.Ala8GlyfsTer6) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (no stars). Synonymous variant affecting the same amino acid position (i.e. A8A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 34)
• Consequence: CRTAP NM_006371.5 frameshift
• Clinical Significance: Pathogenic no assertion criteria provided P:2
• Conservation: PhyloP100: 0.118
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• osteogenesis imperfecta type 7

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• osteogenesis imperfecta type 2

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• osteogenesis imperfecta type 3

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• osteogenesis imperfecta type 4

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 53 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-33114093-C-CGG is Pathogenic according to our data. Variant chr3-33114093-C-CGG is described in ClinVar as Pathogenic. ClinVar VariationId is 1175017.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRTAP	NM_006371.5	c.21_22dupGG	p.Ala8GlyfsTer6	frameshift_variant	Exon 1 of 7	ENST00000320954.11	NP_006362.1
CRTAP	NM_001393363.1	c.21_22dupGG	p.Ala8GlyfsTer6	frameshift_variant	Exon 1 of 6		NP_001380292.1
CRTAP	NM_001393364.1	c.21_22dupGG	p.Ala8GlyfsTer6	frameshift_variant	Exon 1 of 6		NP_001380293.1
CRTAP	NM_001393365.1	c.21_22dupGG	p.Ala8GlyfsTer6	frameshift_variant	Exon 1 of 6		NP_001380294.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRTAP	ENST00000320954.11	c.21_22dupGG	p.Ala8GlyfsTer6	frameshift_variant	Exon 1 of 7	1	NM_006371.5	ENSP00000323696.5
CRTAP	ENST00000449224.1	c.21_22dupGG	p.Ala8GlyfsTer6	frameshift_variant	Exon 1 of 6	2		ENSP00000409997.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: no assertion criteria provided

Submissions by phenotype

not provided Pathogenic:2

-

Genome Diagnostics Laboratory, Amsterdam University Medical Center

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

-

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.12
Mutation Taster		=3/197	disease causing (fs/PTC)

Splicing

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

Other links and lift over

dbSNP: rs137853936; hg19: chr3-33155585;