12-47973379-G-A

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BS1 BS2

The NM_001844.5(COL2A1):c.*28C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000601 in 1,614,144 control chromosomes in the GnomAD database, including 6 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00084 (1 hom., cov: 32)
  • Exomes 𝑓: 0.00058 (5 hom.)
• Consequence: COL2A1 NM_001844.5 3_prime_UTR
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: 0.690

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 Benign. Variant got -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.66).
• BP6: Variant 12-47973379-G-A is Benign according to our data. Variant chr12-47973379-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 308901.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.000841 (128/152264) while in subpopulation EAS AF= 0.0199 (103/5186). AF 95% confidence interval is 0.0168. There are 1 homozygotes in gnomad4. There are 85 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High AC in GnomAd at 129 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL2A1	NM_001844.5	c.*28C>T		3_prime_UTR_variant	54/54	ENST00000380518.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL2A1	ENST00000380518.8	c.*28C>T		3_prime_UTR_variant	54/54	1	NM_001844.5	P1
COL2A1	ENST00000493991.5	n.3578C>T		non_coding_transcript_exon_variant	37/37	2
COL2A1	ENST00000337299.7			downstream_gene_variant		1

Frequencies

GnomAD3 genomes AF: 0.000848 AC: 129 AN: 152146 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.0000724

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.0200

Gnomad SAS AF: 0.00249

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000103

Gnomad OTH AF: 0.00143

GnomAD3 exomes AF: 0.00150 AC: 377 AN: 251496 Hom.: 4 AF XY: 0.00144 AC XY: 196 AN XY: 135922

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.0000867

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0187

Gnomad SAS exome AF: 0.000555

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000703

Gnomad OTH exome AF: 0.000651

GnomAD4 exome AF: 0.000576 AC: 842 AN: 1461880 Hom.: 5 Cov.: 31 AF XY: 0.000600 AC XY: 436 AN XY: 727242

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.000112

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0165

Gnomad4 SAS exome AF: 0.000754

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000710

Gnomad4 OTH exome AF: 0.000596

GnomAD4 genome AF: 0.000841 AC: 128 AN: 152264 Hom.: 1 Cov.: 32 AF XY: 0.00114 AC XY: 85 AN XY: 74450

Gnomad4 AFR AF: 0.0000722

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.0199

Gnomad4 SAS AF: 0.00249

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000103

Gnomad4 OTH AF: 0.00142

Alfa AF: 0.000253 Hom.: 0

Bravo AF: 0.000771

Asia WGS AF: 0.00606 AC: 21 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Stickler syndrome type 1 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Jun 14, 2018

- -

Type II Collagenopathies Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.66
Cadd	Benign	12
Dann	Benign	0.85
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs41272775; hg19: chr12-48367162;