12-47974835-C-T

Variant names:

• chr12-47974835-C-T
• rs121912887
• NM_001844.5:c.3914G>A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Moderate

The NM_001844.5(COL2A1):​c.3914G>A​(p.Gly1305Asp) 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL2A1 NM_001844.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter 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 11 ACMG points.

• PM1: In a disulfide_bond (size 32) in uniprot entity CO2A1_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_001844.5
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the COL2A1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 376 curated pathogenic missense variants (we use a threshold of 10). The gene has 125 curated benign missense variants. Gene score misZ: 3.2926 (above the threshold of 3.09). Trascript score misZ: 5.3726 (above the threshold of 3.09). GenCC associations: The gene is linked to spondylometaphyseal dysplasia, Schmidt type, spondyloepiphyseal dysplasia congenita, hypochondrogenesis, autosomal dominant rhegmatogenous retinal detachment, spondyloperipheral dysplasia, Kniest dysplasia, familial avascular necrosis of femoral head, spondylometaphyseal dysplasia, mild spondyloepiphyseal dysplasia due to COL2A1 mutation with early-onset osteoarthritis, otospondylomegaepiphyseal dysplasia, autosomal recessive, multiple epiphyseal dysplasia, Beighton type, otospondylomegaepiphyseal dysplasia, Legg-Calve-Perthes disease, achondrogenesis type II, spondyloepiphyseal dysplasia, Stanescu type, platyspondylic dysplasia, Torrance type, Stickler syndrome type 1, dysspondyloenchondromatosis, vitreoretinopathy with phalangeal epiphyseal dysplasia, Stickler syndrome, type I, nonsyndromic ocular, avascular necrosis of femoral head, primary, 1, spondyloepiphyseal dysplasia with metatarsal shortening, spondyloepimetaphyseal dysplasia, Strudwick type.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 12-47974835-C-T is Pathogenic according to our data. Variant chr12-47974835-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 17387.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr12-47974835-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL2A1	NM_001844.5	c.3914G>A	p.Gly1305Asp	missense_variant	Exon 52 of 54	ENST00000380518.8	NP_001835.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL2A1	ENST00000380518.8	c.3914G>A	p.Gly1305Asp	missense_variant	Exon 52 of 54	1	NM_001844.5	ENSP00000369889.3
COL2A1	ENST00000337299.7	c.3707G>A	p.Gly1236Asp	missense_variant	Exon 51 of 53	1		ENSP00000338213.6
COL2A1	ENST00000493991.5	n.3000G>A		non_coding_transcript_exon_variant	Exon 35 of 37	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Feb 07, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 1305 of the COL2A1 protein (p.Gly1305Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with vitreoretinopathy with phalangeal epiphyseal dysplasia (PMID: 12205109). It has also been observed to segregate with disease in related individuals. This variant is also known as G1105D. ClinVar contains an entry for this variant (Variation ID: 17387). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt COL2A1 protein function with a positive predictive value of 95%. This variant disrupts the p.Gly1305 amino acid residue in COL2A1. Other variant(s) that disrupt this residue have been determined to be pathogenic (Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Vitreoretinopathy with phalangeal epiphyseal dysplasia Pathogenic:1

Sep 01, 2002

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;.
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	3.9	H;.
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-6.3	D;D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.028	D;D
Polyphen		1.0	D;D
Vest4		0.96
MutPred		0.96		Gain of relative solvent accessibility (P = 0.09);.;
MVP		0.96
MPC		0.41
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.92
gMVP		0.77

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: rs121912887; hg19: chr12-48368618;