20-62838713-G-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting

The NM_001853.4(COL9A3):c.1816G>T(p.Ala606Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000171 in 1,552,702 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A606V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00018 ( 0 hom. )

Consequence

COL9A3
NM_001853.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: -0.836

Publications

8 publications found

Variant links:

Genes affected

COL9A3 (HGNC:2219): (collagen type IX alpha 3 chain) This gene encodes one of the three alpha chains of type IX collagen, the major collagen component of hyaline cartilage. Type IX collagen, a heterotrimeric molecule, is usually found in tissues containing type II collagen, a fibrillar collagen. Mutations in this gene are associated with multiple epiphyseal dysplasia type 3. [provided by RefSeq, Jan 2010]

COL9A3 Gene-Disease associations (from GenCC):

epiphyseal dysplasia, multiple, 3
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Illumina, G2P, Labcorp Genetics (formerly Invitae)
Stickler syndrome
Inheritance: AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Ambry Genetics, Genomics England PanelApp, ClinGen
Stickler syndrome, type 6
Inheritance: AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
multiple epiphyseal dysplasia due to collagen 9 anomaly
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
autosomal recessive Stickler syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

COL9A3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.04832554).

BS1

Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.000182 (255/1400516) while in subpopulation NFE AF = 0.000232 (251/1079568). AF 95% confidence interval is 0.000209. There are 0 homozygotes in GnomAdExome4. There are 115 alleles in the male GnomAdExome4 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
COL9A3	NM_001853.4 link	c.1816G>T	p.Ala606Ser	missense_variant	Exon 31 of 32	ENST00000649368.1	NP_001844.3
COL9A3	XM_047439893.1 link	c.1993G>T	p.Ala665Ser	missense_variant	Exon 30 of 31		XP_047295849.1
COL9A3	XM_047439894.1 link	c.1255G>T	p.Ala419Ser	missense_variant	Exon 31 of 32		XP_047295850.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL9A3	ENST00000649368.1 link	c.1816G>T	p.Ala606Ser	missense_variant	Exon 31 of 32		NM_001853.4	ENSP00000496793.1

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152186

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

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:

0.000103

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000253

AC:

AN:

158024

AF XY:

0.0000361

show subpopulations

Gnomad AFR exome

AF:

0.000113

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000488

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000182

AC:

255

AN:

1400516

Hom.:

Cov.:

AF XY:

0.000166

AC XY:

115

AN XY:

690876

show subpopulations

African (AFR)

AF:

0.0000316

AC:

AN:

31652

American (AMR)

AF:

0.00

AC:

AN:

35824

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25188

East Asian (EAS)

AF:

0.00

AC:

AN:

35874

South Asian (SAS)

AF:

0.00

AC:

AN:

79274

European-Finnish (FIN)

AF:

0.00

AC:

AN:

49362

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5698

European-Non Finnish (NFE)

AF:

0.000233

AC:

251

AN:

1079568

Other (OTH)

AF:

0.0000517

AC:

AN:

58076

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.455

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

100

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000723

AC:

AN:

152186

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74352

show subpopulations

African (AFR)

AF:

0.0000965

AC:

AN:

41436

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5202

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000103

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.539

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000491

ExAC

AF:

0.0000101

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Jul 15, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Has not been previously published as pathogenic or benign to our knowledge; In silico analysis indicates that this missense variant does not alter protein structure/function

Aug 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 606 of the COL9A3 protein (p.Ala606Ser). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with COL9A3-related conditions. ClinVar contains an entry for this variant (Variation ID: 1475124). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt COL9A3 protein function with a negative predictive value of 95%. 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.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.070

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.32

CADD

Benign

0.021

(source)

DANN

Benign

0.67

DEOGEN2

Benign

0.11

T;T

Eigen

Benign

-1.3

Eigen_PC

Benign

-1.3

FATHMM_MKL

Benign

0.057

LIST_S2

Benign

0.0

.;T

M_CAP

Benign

0.059

MetaRNN

Benign

0.048

T;T

MetaSVM

Benign

-0.57

MutationAssessor

Benign

0.95

L;L

PhyloP100

-0.84

PrimateAI

Benign

0.23

PROVEAN

Benign

0.0

.;N

REVEL

Benign

0.0

Sift

Pathogenic

0.0

.;T

Sift4G

Pathogenic

0.0

.;T

Vest4

0.0

ClinPred

0.0072

GERP RS

-0.78

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.020

gMVP

0.31

Mutation Taster

=98/2

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over