rs886042651

Positions:

• chr12-47975986-G-A
• chr12-47975986-G-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001844.5(COL2A1):​c.3574C>T​(p.Arg1192Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000656 in 152,336 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: COL2A1 NM_001844.5 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 3.24

Genes affected

COL2A1 (HGNC:2200): (collagen type II alpha 1 chain) This gene encodes the alpha-1 chain of type II collagen, a fibrillar collagen found in cartilage and the vitreous humor of the eye. Mutations in this gene are associated with achondrogenesis, chondrodysplasia, early onset familial osteoarthritis, SED congenita, Langer-Saldino achondrogenesis, Kniest dysplasia, Stickler syndrome type I, and spondyloepimetaphyseal dysplasia Strudwick type. In addition, defects in processing chondrocalcin, a calcium binding protein that is the C-propeptide of this collagen molecule, are also associated with chondrodysplasia. There are two transcripts identified for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-47975986-G-A is Pathogenic according to our data. Variant chr12-47975986-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 283534.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-47975986-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL2A1	NM_001844.5	c.3574C>T	p.Arg1192Ter	stop_gained	50/54	ENST00000380518.8	NP_001835.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL2A1	ENST00000380518.8	c.3574C>T	p.Arg1192Ter	stop_gained	50/54	1	NM_001844.5	ENSP00000369889	P1
COL2A1	ENST00000337299.7	c.3367C>T	p.Arg1123Ter	stop_gained	49/53	1		ENSP00000338213
COL2A1	ENST00000546974.1	n.427C>T		non_coding_transcript_exon_variant	5/6	1
COL2A1	ENST00000493991.5	n.2660C>T		non_coding_transcript_exon_variant	33/37	2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152218 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000656 AC: 1 AN: 152336 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74488

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 19, 2023	This sequence change creates a premature translational stop signal (p.Arg1192*) in the COL2A1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in COL2A1 are known to be pathogenic (PMID: 20179744). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with Stickler syndrome (PMID: 18276201, 20179744, 26626311). ClinVar contains an entry for this variant (Variation ID: 283534). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Apr 26, 2022	Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 18276201, 25525159, 20179744, 29453417, 26626311, 34313156, 28832562, 32756486) -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 29, 2015	- -

COL2A1-related disorder Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 15, 2024

The COL2A1 c.3574C>T variant is predicted to result in premature protein termination (p.Arg1192*). This variant has been reported as causative for Stickler syndrome (see for examples: Zechi-Ceide et al. 2008. PubMed ID: 18276201; Barat-Houari et al. 2015. PubMed ID: 26626311; Hoornaert et al. 2010. PubMed ID: 20179744). This variant has not been reported in a large population database, indicating this variant is rare. Nonsense variants in COL2A1 are an established mechanism of disease. This variant is interpreted as pathogenic. -

Spondyloepiphyseal dysplasia congenita Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

DASA

Mar 05, 2022

The c.3574C>T;p.(Arg1192*) variant creates a premature translational stop signal in the COL2A1 gene. It is expected to result in an absent or disrupted protein product - PVS1. This sequence change has been observed in affected individual(s) and ClinVar contains an entry for this variant (ClinVar ID: 283534; PMID: 18276201; PMID: 26626311; PMID: 20179744) - PS4. This variant is not present in population databases (rs886042651- gnomAD; ABraOM no frequency - http://abraom.ib.usp.br/) - PM2. In summary, the currently available evidence indicates that the variant is pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.68	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	49
DANN	Uncertain	1.0
Eigen	Pathogenic	0.79
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Pathogenic	0.97	D
MutationTaster	Benign	1.0	A;A
Vest4		0.96
GERP RS		4.2
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

Other links and lift over

dbSNP: rs886042651; hg19: chr12-48369769; COSMIC: COSV61527904;