rs672601329

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2PP3_ModerateBS1_Supporting

The NM_001851.6(COL9A1):c.876+2_876+3insT variant causes a splice region, intron change. The variant allele was found at a frequency of 0.000309 in 1,610,516 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00031 ( 0 hom., cov: 31)

Exomes 𝑓: 0.00031 ( 0 hom. )

Consequence

COL9A1
NM_001851.6 splice_region, intron

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:4

Conservation

PhyloP100: 6.21

Variant links:

Genes affected

COL9A1 (HGNC:2217): (collagen type IX alpha 1 chain) This gene encodes one of the three alpha chains of type IX collagen, which is a minor (5-20%) collagen component of hyaline cartilage. Type IX collagen is usually found in tissues containing type II collagen, a fibrillar collagen. Studies in knockout mice have shown that synthesis of the alpha 1 chain is essential for assembly of type IX collagen molecules, a heterotrimeric molecule, and that lack of type IX collagen is associated with early onset osteoarthritis. Mutations in this gene are associated with osteoarthritis in humans, with multiple epiphyseal dysplasia, 6, a form of chondrodysplasia, and with Stickler syndrome, a disease characterized by ophthalmic, orofacial, articular, and auditory defects. Two transcript variants that encode different isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]

COL9A1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.000313 (47/150394) while in subpopulation NFE AF= 0.000636 (43/67624). AF 95% confidence interval is 0.000484. There are 0 homozygotes in gnomad4. There are 22 alleles in male gnomad4 subpopulation. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL9A1	NM_001851.6 linkuse as main transcript	c.876+2_876+3insT		splice_region_variant, intron_variant		ENST00000357250.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL9A1	ENST00000357250.11 linkuse as main transcript	c.876+2_876+3insT		splice_region_variant, intron_variant		1	NM_001851.6	P1	P20849-1

Frequencies

GnomAD3 genomes

AF:

0.000313

AC:

AN:

150346

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000736

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000636

Gnomad OTH

AF:

0.000485

GnomAD3 exomes

AF:

0.000211

AC:

AN:

250708

Hom.:

AF XY:

0.000251

AC XY:

AN XY:

135600

show subpopulations

Gnomad AFR exome

AF:

0.0000620

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000164

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000406

Gnomad OTH exome

AF:

0.000164

GnomAD4 exome

AF:

0.000308

AC:

450

AN:

1460122

Hom.:

Cov.:

AF XY:

0.000324

AC XY:

235

AN XY:

726430

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000128

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000376

Gnomad4 OTH exome

AF:

0.000332

GnomAD4 genome

AF:

0.000313

AC:

AN:

150394

Hom.:

Cov.:

AF XY:

0.000300

AC XY:

AN XY:

73402

show subpopulations

Gnomad4 AFR

AF:

0.0000735

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000636

Gnomad4 OTH

AF:

0.000480

EpiCase

AF:

0.000382

EpiControl

AF:

0.000296

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Dec 01, 2022	COL9A1: PP3, PS3:Supporting -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Oct 13, 2022	This sequence change falls in intron 8 of the COL9A1 gene. It does not directly change the encoded amino acid sequence of the COL9A1 protein. RNA analysis indicates that this variant induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs672601329, gnomAD 0.04%). This variant has been observed in individual(s) with multiple epiphyseal dysplasia (PMID: 11565064). ClinVar contains an entry for this variant (Variation ID: 17194). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exons 8 and/or 10, but is expected to preserve the integrity of the reading-frame (PMID: 11565064). 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. -

Epiphyseal dysplasia, multiple, 6

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 2001

- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 02, 2017

A variant of uncertain significance has been identified in the COL9A1 gene. The c.876+2dupT variant has not been published as pathogenic or been reported as benign to our knowledge. This variant is not observed in large population cohorts (Lek et al., 2016). The c.876+2duptT variant is predicted to destroy the canonical splice donor site in intron 8 with the adjacent exon remaining inframe. This variant may result in abnormal gene splicing; however, in the absence of functional mRNA studies, the physiological consequence of this variant cannot be precisely determined. -

Epiphyseal dysplasia, multiple, 6;C3279941:Stickler syndrome, type 4

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Mar 08, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.93

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.93

Position offset: 3

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over