chr20-62826241-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PP3_Strong

The NM_001853.4(COL9A3):​c.722G>C​(p.Gly241Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000232 in 1,555,022 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G241R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

COL9A3
NM_001853.4 missense

Scores

12
5
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.23

Publications

1 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 4 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.992

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001853.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL9A3
NM_001853.4
MANE Select
c.722G>Cp.Gly241Ala
missense
Exon 14 of 32NP_001844.3

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL9A3
ENST00000649368.1
MANE Select
c.722G>Cp.Gly241Ala
missense
Exon 14 of 32ENSP00000496793.1
COL9A3
ENST00000463487.2
TSL:5
n.430G>C
non_coding_transcript_exon
Exon 6 of 11
COL9A3
ENST00000489045.5
TSL:5
n.768G>C
non_coding_transcript_exon
Exon 13 of 14

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152162
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000128
AC:
2
AN:
156472
AF XY:
0.0000120
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:
0.0000335
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000235
AC:
33
AN:
1402860
Hom.:
0
Cov.:
33
AF XY:
0.0000173
AC XY:
12
AN XY:
692774
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32042
American (AMR)
AF:
0.00
AC:
0
AN:
36646
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25190
East Asian (EAS)
AF:
0.00
AC:
0
AN:
36492
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79676
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47118
Middle Eastern (MID)
AF:
0.000186
AC:
1
AN:
5376
European-Non Finnish (NFE)
AF:
0.0000296
AC:
32
AN:
1082196
Other (OTH)
AF:
0.00
AC:
0
AN:
58124
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
3
6
8
11
14
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:
0.0000197
AC:
3
AN:
152162
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74332
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41436
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68006
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.592
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000843
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Mar 28, 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; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function

Nov 25, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 241 of the COL9A3 protein (p.Gly241Ala). This variant is present in population databases (no rsID available, gnomAD 0.004%). 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: 521579). 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 expected to disrupt COL9A3 protein function with a positive 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.

Inborn genetic diseases Uncertain:1
Feb 14, 2017
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.46
BayesDel_addAF
Pathogenic
0.39
D
BayesDel_noAF
Pathogenic
0.43
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Benign
0.15
T
Eigen
Pathogenic
0.73
Eigen_PC
Uncertain
0.55
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.96
D
M_CAP
Pathogenic
0.97
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.3
H
PhyloP100
7.2
PrimateAI
Pathogenic
0.84
D
PROVEAN
Pathogenic
-5.5
D
REVEL
Pathogenic
0.93
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.83
MutPred
0.99
Loss of catalytic residue at P237 (P = 0.0761)
MVP
0.86
MPC
0.076
ClinPred
0.98
D
GERP RS
3.7
RBP_binding_hub_radar
1.0
RBP_regulation_power_radar
2.8
Varity_R
0.87
gMVP
0.97
Mutation Taster
=82/18
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: rs991678832; hg19: chr20-61457593; API