chr6-70234894-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BS1_Supporting

The NM_001851.6(COL9A1):c.2159G>A(p.Arg720Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000537 in 1,614,144 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R720W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00041 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00055 ( 1 hom. )

Consequence

COL9A1
NM_001851.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 7.82

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:

ENSG00000253809 (HGNC:):

ENSG00000253809 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000407 (62/152274) while in subpopulation NFE AF = 0.000691 (47/68012). AF 95% confidence interval is 0.000534. There are 0 homozygotes in GnomAd4. There are 24 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL9A1	NM_001851.6 link	c.2159G>A	p.Arg720Gln	missense_variant	Exon 34 of 38	ENST00000357250.11	NP_001842.3	P20849-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL9A1	ENST00000357250.11 link	c.2159G>A	p.Arg720Gln	missense_variant	Exon 34 of 38	1	NM_001851.6	ENSP00000349790.6		P20849-1

Frequencies

GnomAD3 genomes

AF:

0.000407

AC:

AN:

152156

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000193

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000386

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000691

Gnomad OTH

AF:

0.000955

GnomAD2 exomes

AF:

0.000442

AC:

111

AN:

251252

AF XY:

0.000427

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.000289

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.000218

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000801

Gnomad OTH exome

AF:

0.000489

GnomAD4 exome

AF:

0.000550

AC:

804

AN:

1461870

Hom.:

Cov.:

AF XY:

0.000586

AC XY:

426

AN XY:

727236

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33480

American (AMR)

AF:

0.000224

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.0000765

AC:

AN:

26136

East Asian (EAS)

AF:

0.000151

AC:

AN:

39696

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.0000562

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000676

AC:

752

AN:

1112004

Other (OTH)

AF:

0.000414

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.477

Heterozygous variant carriers

110

165

220

275

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.000407

AC:

AN:

152274

Hom.:

Cov.:

AF XY:

0.000322

AC XY:

AN XY:

74468

show subpopulations

African (AFR)

AF:

0.000193

AC:

AN:

41550

American (AMR)

AF:

0.000196

AC:

AN:

15298

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.000387

AC:

AN:

5174

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

292

European-Non Finnish (NFE)

AF:

0.000691

AC:

AN:

68012

Other (OTH)

AF:

0.000945

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00193

Hom.:

Bravo

AF:

0.000389

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000698

AC:

ExAC

AF:

0.000445

AC:

EpiCase

AF:

0.000382

EpiControl

AF:

0.000474

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3Benign:1

Jan 27, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 17, 2016

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 05, 2015

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mar 04, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported as a heterozygous variant in one individual undergoing exome sequencing for retinitis pigmentosa (PMID: 27353947), but has not been published in association with a known COL9A1-related phenotype to our knowledge; In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 27353947) -

Optic atrophy

Uncertain:1

Jan 01, 2023

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Retinal dystrophy

Uncertain:1

Jan 01, 2023

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.20

BayesDel_noAF

Benign

-0.14

CADD

Uncertain

(source)

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.39

T;.

Eigen

Uncertain

0.25

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

D;D

M_CAP

Benign

0.071

MetaRNN

Uncertain

0.43

T;T

MetaSVM

Uncertain

-0.27

MutationAssessor

Benign

0.21

N;.

PhyloP100

7.8

PrimateAI

Uncertain

0.59

PROVEAN

Benign

-1.7

N;N

REVEL

Uncertain

0.45

Sift

Uncertain

0.024

D;T

Sift4G

Benign

0.59

T;T

Polyphen

1.0

D;D

Vest4

0.71

MVP

0.88

MPC

0.44

ClinPred

0.23

GERP RS

4.9

Varity_R

0.26

gMVP

0.35

Mutation Taster

=73/27

polymorphism

(source)

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

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

chr6-70234894-C-T

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over