12-47973412-A-T

Variant names:

• chr12-47973412-A-T
• rs1938531475
• NM_001844.5:c.4459T>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001844.5(COL2A1):​c.4459T>A​(p.Leu1487Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: COL2A1 NM_001844.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.04
• Publications: 0 publications found

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]

COL2A1 Gene-Disease associations (from GenCC):

• achondrogenesis type II

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, ClinGen, G2P, Orphanet, Labcorp Genetics (formerly Invitae)
• Kniest dysplasia

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, ClinGen, Labcorp Genetics (formerly Invitae)
• platyspondylic dysplasia, Torrance type

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• spondyloepimetaphyseal dysplasia, Strudwick type

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
• spondyloepiphyseal dysplasia congenita

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, G2P, Orphanet, Labcorp Genetics (formerly Invitae)
• spondyloepiphyseal dysplasia with metatarsal shortening

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: ClinGen, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• spondylometaphyseal dysplasia

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• spondyloperipheral dysplasia

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Stickler syndrome type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, ClinGen, Illumina, Orphanet, Genomics England PanelApp
• Stickler syndrome, type I, nonsyndromic ocular

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• avascular necrosis of femoral head, primary, 1

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Legg-Calve-Perthes disease

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• mild spondyloepiphyseal dysplasia due to COL2A1 mutation with early-onset osteoarthritis

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• otospondylomegaepiphyseal dysplasia, autosomal recessive

  Inheritance: AD, AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
• spondyloepiphyseal dysplasia, Stanescu type

  Inheritance: AD Classification: MODERATE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• autosomal dominant rhegmatogenous retinal detachment

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• dysspondyloenchondromatosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial avascular necrosis of femoral head

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hypochondrogenesis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• multiple epiphyseal dysplasia, Beighton type

  Inheritance: AD Classification: SUPPORTIVE, LIMITED Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• spondylometaphyseal dysplasia, Schmidt type

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• otospondylomegaepiphyseal dysplasia

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
• vitreoretinopathy with phalangeal epiphyseal dysplasia

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• 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 vitreoretinopathy with phalangeal epiphyseal dysplasia, Stickler syndrome, type I, nonsyndromic ocular, Kniest dysplasia, Stickler syndrome type 1, platyspondylic dysplasia, Torrance type, spondyloepiphyseal dysplasia with metatarsal shortening, spondyloperipheral dysplasia, spondyloepiphyseal dysplasia, Stanescu type, Legg-Calve-Perthes disease, achondrogenesis type II, spondyloepiphyseal dysplasia congenita, multiple epiphyseal dysplasia, Beighton type, mild spondyloepiphyseal dysplasia due to COL2A1 mutation with early-onset osteoarthritis, autosomal dominant rhegmatogenous retinal detachment, spondylometaphyseal dysplasia, spondyloepimetaphyseal dysplasia, Strudwick type, familial avascular necrosis of femoral head, dysspondyloenchondromatosis, spondylometaphyseal dysplasia, Schmidt type, hypochondrogenesis, otospondylomegaepiphyseal dysplasia, autosomal recessive, otospondylomegaepiphyseal dysplasia, avascular necrosis of femoral head, primary, 1.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL2A1	NM_001844.5	c.4459T>A	p.Leu1487Met	missense_variant	Exon 54 of 54	ENST00000380518.8	NP_001835.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL2A1	ENST00000380518.8	c.4459T>A	p.Leu1487Met	missense_variant	Exon 54 of 54	1	NM_001844.5	ENSP00000369889.3
COL2A1	ENST00000337299.7	c.4252T>A	p.Leu1418Met	missense_variant	Exon 53 of 53	1		ENSP00000338213.6
COL2A1	ENST00000493991.5	n.3545T>A		non_coding_transcript_exon_variant	Exon 37 of 37	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461894 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727248

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Apr 12, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 not expected to disrupt COL2A1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This sequence change replaces leucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 1487 of the COL2A1 protein (p.Leu1487Met). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with COL2A1-related conditions. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Uncertain	23
DANN	Uncertain	0.98
DEOGEN2	Benign	0.27	T;.
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.77	T;T
M_CAP	Pathogenic	0.34	D
MetaRNN	Uncertain	0.58	D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.3	M;.
PhyloP100		2.0
PrimateAI	Uncertain	0.67	T
PROVEAN	Benign	-0.16	N;N
REVEL	Pathogenic	0.75
Sift	Benign	0.032	D;D
Sift4G	Uncertain	0.042	D;D
Polyphen		1.0	D;D
Vest4		0.38
MutPred		0.65		Gain of disorder (P = 0.0336);.;
MVP		0.72
MPC		0.31
ClinPred		0.86	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.23
gMVP		0.40
Mutation Taster		=60/40	polymorphism

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

Other links and lift over

dbSNP: rs1938531475; hg19: chr12-48367195;