rs121912899

chr12-47985771-C-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_001844.5(COL2A1):c.1637G>T(p.Gly546Val) 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 (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G546S) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL2A1 NM_001844.5 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.86

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 12 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 4 uncertain in NM_001844.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-47985772-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 290774.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant where missense usually causes diseases, COL2A1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 12-47985771-C-A is Pathogenic according to our data. Variant chr12-47985771-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 17403.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr12-47985771-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL2A1	NM_001844.5	c.1637G>T	p.Gly546Val	missense_variant	25/54	ENST00000380518.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL2A1	ENST00000380518.8	c.1637G>T	p.Gly546Val	missense_variant	25/54	1	NM_001844.5	P1
COL2A1	ENST00000337299.7	c.1430G>T	p.Gly477Val	missense_variant	24/53	1
COL2A1	ENST00000493991.5	n.561G>T		non_coding_transcript_exon_variant	8/37	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Achondrogenesis type II Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Dec 01, 2007

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
Cadd	Pathogenic	27
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.93	D
MetaRNN	Pathogenic	1.0	D;D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	4.0	H;.
MutationTaster	Benign	1.0	A;A
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-7.5	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 methylation at R550 (P = 0.2013);.;
MVP		0.99
MPC		2.0
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6
Varity_R		0.94
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: rs121912899; hg19: chr12-48379554;