12-47983384-C-T

Variant names:

• chr12-47983384-C-T
• rs1555166658
• NM_001844.5:c.2049+1G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_001844.5(COL2A1):​c.2049+1G>A variant causes a splice donor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: COL2A1 NM_001844.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.03
• 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: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.012096774 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.5, offset of -8, new splice context is: cagGTgacc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-47983384-C-T is Pathogenic according to our data. Variant chr12-47983384-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 547254.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL2A1	NM_001844.5	c.2049+1G>A		splice_donor_variant, intron_variant	Intron 31 of 53	ENST00000380518.8	NP_001835.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL2A1	ENST00000380518.8	c.2049+1G>A		splice_donor_variant, intron_variant	Intron 31 of 53	1	NM_001844.5	ENSP00000369889.3
COL2A1	ENST00000337299.7	c.1842+1G>A		splice_donor_variant, intron_variant	Intron 30 of 52	1		ENSP00000338213.6
COL2A1	ENST00000483376.1	n.227+1G>A		splice_donor_variant, intron_variant	Intron 2 of 7	5
COL2A1	ENST00000493991.5	n.973+1G>A		splice_donor_variant, intron_variant	Intron 14 of 36	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Stickler syndrome type 1 Pathogenic:1

Nov 01, 2016

Center for Human Genetics, Inc, Center for Human Genetics, Inc

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.68	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	35
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Uncertain	0.95	D
PhyloP100		5.0
GERP RS		4.9
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.64		Position offset: 9
DS_DL_spliceai		0.98		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1555166658; hg19: chr12-48377167;