rs786205477

chr12-47977363-C-A

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_001844.5(COL2A1):c.3230G>T(p.Gly1077Val) 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. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: COL2A1 NM_001844.5 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.91

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 15 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, COL2A1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 12-47977363-C-A is Pathogenic according to our data. Variant chr12-47977363-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 191036.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL2A1	NM_001844.5	c.3230G>T	p.Gly1077Val	missense_variant	46/54	ENST00000380518.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL2A1	ENST00000380518.8	c.3230G>T	p.Gly1077Val	missense_variant	46/54	1	NM_001844.5	P1
COL2A1	ENST00000337299.7	c.3023G>T	p.Gly1008Val	missense_variant	45/53	1
COL2A1	ENST00000546974.1	n.83G>T		non_coding_transcript_exon_variant	1/6	1
COL2A1	ENST00000493991.5	n.2316G>T		non_coding_transcript_exon_variant	29/37	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Oct 07, 2019	The COL2A1 c.3230G>T; p.Gly1077Val variant (rs786205477), to our knowledge, is not described in the medical literature but is reported in ClinVar (Variation ID: 191036). This variant is absent from general population databases (Exome Variant Server and Genome Aggregation Database), indicating it is not a common polymorphism. The glycine at codon 1077 is highly conserved, and computational analyses (SIFT, PolyPhen-2) predict that this variant is deleterious. This variant disrupts the repeating Gly-X-Y sequence motif of the collagen triple helix and is predicted to impair collagen function (Barat-Houari 2016). Based on available information, this variant is considered to be likely pathogenic. References: Barat-Houari M et al. Mutation Update for COL2A1 Gene Variants Associated with Type II Collagenopathies. Hum Mutat. 2016 Jan;37(1):7-15. -
Likely pathogenic, criteria provided, single submitter	research	Department Of Translational Genomics (developmental Genetics Section), King Faisal Specialist Hospital & Research Centre	-	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
Cadd	Pathogenic	27
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.92	D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Pathogenic	4.0	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-7.6	D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0010	D;D
Polyphen		1.0	D;D
Vest4		0.99
MutPred		1.0		Loss of glycosylation at P1076 (P = 0.0959);.;
MVP		0.98
MPC		0.39
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.92
gMVP		1.0

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: rs786205477; hg19: chr12-48371146;