NM_000095.3:c.1403G>T

Variant names:

• chr19-18786051-C-A
• rs137852651
• NM_000095.3:c.1403G>T

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Moderate

The NM_000095.3(COMP):​c.1403G>T​(p.Cys468Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C468Y) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COMP NM_000095.3 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.76
• Publications: 0 publications found

Genes affected

COMP (HGNC:2227): (cartilage oligomeric matrix protein) The protein encoded by this gene is a noncollagenous extracellular matrix (ECM) protein. It consists of five identical glycoprotein subunits, each with EGF-like and calcium-binding (thrombospondin-like) domains. Oligomerization results from formation of a five-stranded coiled coil and disulfides. Binding to other ECM proteins such as collagen appears to depend on divalent cations. Contraction or expansion of a 5 aa aspartate repeat and other mutations can cause pseudochondroplasia (PSACH) and multiple epiphyseal dysplasia (MED). [provided by RefSeq, Jul 2016]

COMP Gene-Disease associations (from GenCC):

• multiple epiphyseal dysplasia

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• pseudoachondroplasia

  Inheritance: AD, Unknown Classification: DEFINITIVE, STRONG, SUPPORTIVE, LIMITED Submitted by: ClinGen, Orphanet, Labcorp Genetics (formerly Invitae), Illumina
• multiple epiphyseal dysplasia type 1

  Inheritance: AD Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Pathogenic. The variant received 13 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000095.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-18786052-A-G is described in ClinVar as Pathogenic. ClinVar VariationId is 2862149.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 127 curated pathogenic missense variants (we use a threshold of 10). The gene has 12 curated benign missense variants. Gene score misZ: 1.78 (below the threshold of 3.09). Trascript score misZ: 1.5018 (below the threshold of 3.09). GenCC associations: The gene is linked to pseudoachondroplasia, multiple epiphyseal dysplasia type 1, multiple epiphyseal dysplasia.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97
• PP5: Variant 19-18786051-C-A is Pathogenic according to our data. Variant chr19-18786051-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 1180714.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COMP	NM_000095.3	c.1403G>T	p.Cys468Phe	missense_variant	Exon 13 of 19	ENST00000222271.7	NP_000086.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COMP	ENST00000222271.7	c.1403G>T	p.Cys468Phe	missense_variant	Exon 13 of 19	1	NM_000095.3	ENSP00000222271.2
COMP	ENST00000542601.6	c.1304G>T	p.Cys435Phe	missense_variant	Exon 12 of 18	1		ENSP00000439156.2
COMP	ENST00000425807.1	c.1244G>T	p.Cys415Phe	missense_variant	Exon 12 of 18	2		ENSP00000403792.1
COMP	ENST00000612179.1	n.*67G>T		downstream_gene_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Abnormality of the skeletal system Pathogenic:1

Jul 10, 2021

Kariminejad - Najmabadi Pathology & Genetics Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	31
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	1.0	.;D;.
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D;D;D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.97	D;D;D
MetaSVM	Pathogenic	0.85	D
MutationAssessor	Pathogenic	3.2	.;M;.
PhyloP100		7.8
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-9.6	D;D;D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.91
MutPred		0.78		.;Gain of catalytic residue at C468 (P = 0.026);.;
MVP		0.97
ClinPred		1.0	D
GERP RS		4.0
Varity_R		1.0
gMVP		0.96
Mutation Taster		=0/100	disease causing

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

Other links and lift over

dbSNP: rs137852651; hg19: chr19-18896861;