rs137852655

Variant names:

• chr19-18783125-C-T
• rs137852655
• NM_000095.3:c.2156G>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000095.3(COMP):​c.2156G>A​(p.Gly719Asp) 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. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G719S) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: COMP NM_000095.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 O:1
• Conservation: PhyloP100: 7.75
• Publications: 6 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):

• COMP-related skeletal dysplasia

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• multiple epiphyseal dysplasia

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

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

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

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 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 chr19-18783126-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 40997.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 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, 0.993
• PP5: Variant 19-18783125-C-T is Pathogenic according to our data. Variant chr19-18783125-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 9194.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000095.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COMP	NM_000095.3	MANE Select	c.2156G>A	p.Gly719Asp	missense	Exon 18 of 19	NP_000086.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COMP	ENST00000222271.7	TSL:1 MANE Select	c.2156G>A	p.Gly719Asp	missense	Exon 18 of 19	ENSP00000222271.2	P49747-1
	COMP	ENST00000542601.6	TSL:1	c.2057G>A	p.Gly686Asp	missense	Exon 17 of 18	ENSP00000439156.2	G3XAP6
	COMP	ENST00000944187.1		c.2243G>A	p.Gly748Asp	missense	Exon 19 of 20	ENSP00000614246.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	-	-	Multiple epiphyseal dysplasia type 1 (1)
1	-	-	not provided (1)
1	-	-	Pseudoachondroplasia, severe (1)
-	-	-	Pseudoachondroplastic spondyloepiphyseal dysplasia syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.2	M
PhyloP100		7.7
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-6.6	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.98		Loss of methylation at R718 (P = 0.0386)
MVP		0.95
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.96
gMVP		0.88
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs137852655; hg19: chr19-18893935;