20-62840721-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PVS1_Moderate

The NM_001853.4(COL9A3):​c.2044C>T​(p.Arg682*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000127 in 1,571,734 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. R682R) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

COL9A3
NM_001853.4 stop_gained

Scores

2
1
4

Clinical Significance

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

Conservation

PhyloP100: 0.811

Publications

15 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.00535 CDS is truncated, and there are 0 pathogenic variants in the truncated region.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL9A3NM_001853.4 linkc.2044C>T p.Arg682* stop_gained Exon 32 of 32 ENST00000649368.1 NP_001844.3 Q14050
COL9A3XM_047439893.1 linkc.2221C>T p.Arg741* stop_gained Exon 31 of 31 XP_047295849.1
COL9A3XM_047439894.1 linkc.1483C>T p.Arg495* stop_gained Exon 32 of 32 XP_047295850.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL9A3ENST00000649368.1 linkc.2044C>T p.Arg682* stop_gained Exon 32 of 32 NM_001853.4 ENSP00000496793.1 Q14050

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152012
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.00000558
AC:
1
AN:
179196
AF XY:
0.0000105
show subpopulations
Gnomad AFR exome
AF:
0.00
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:
0.0000135
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000127
AC:
18
AN:
1419722
Hom.:
0
Cov.:
32
AF XY:
0.0000142
AC XY:
10
AN XY:
702156
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32754
American (AMR)
AF:
0.00
AC:
0
AN:
37608
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25378
East Asian (EAS)
AF:
0.00
AC:
0
AN:
37648
South Asian (SAS)
AF:
0.00
AC:
0
AN:
81272
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50686
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5718
European-Non Finnish (NFE)
AF:
0.0000165
AC:
18
AN:
1089836
Other (OTH)
AF:
0.00
AC:
0
AN:
58822
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000132
AC:
2
AN:
152012
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74240
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41350
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68000
Other (OTH)
AF:
0.000478
AC:
1
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
4225

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Dec 29, 2023
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; Not observed at significant frequency in large population cohorts (gnomAD); Nonsense variant predicted to result in protein truncation as the last 3 amino acids are lost, although loss-of-function variants have not been reported downstream of this position in the protein -

Dec 10, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg682*) in the COL9A3 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 3 amino acid(s) of the COL9A3 protein. 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: 1446896). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
37
DANN
Uncertain
0.98
Eigen
Benign
-0.21
Eigen_PC
Benign
-0.53
FATHMM_MKL
Benign
0.31
N
PhyloP100
0.81
Vest4
0.58
GERP RS
0.95
Mutation Taster
=159/41
polymorphism

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

Other links and lift over

dbSNP: rs1048100; hg19: chr20-61472073; API