NM_001851.6:c.2695G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_001851.6(COL9A1):​c.2695G>A​(p.Gly899Ser) variant causes a missense change. The variant allele was found at a frequency of 0.0000223 in 1,614,048 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 (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

COL9A1
NM_001851.6 missense

Scores

10
7
2

Clinical Significance

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

Conservation

PhyloP100: 4.95

Publications

1 publications found
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 Gene-Disease associations (from GenCC):
  • epiphyseal dysplasia, multiple, 6
    Inheritance: AD, AR, Unknown Classification: DEFINITIVE, LIMITED Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • Stickler syndrome, type 4
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, G2P, Genomics England PanelApp, PanelApp Australia, 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
  • Stickler syndrome
    Inheritance: AR Classification: LIMITED Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PP3
MetaRNN computational evidence supports a deleterious effect, 0.907

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL9A1NM_001851.6 linkc.2695G>A p.Gly899Ser missense_variant Exon 38 of 38 ENST00000357250.11 NP_001842.3 P20849-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL9A1ENST00000357250.11 linkc.2695G>A p.Gly899Ser missense_variant Exon 38 of 38 1 NM_001851.6 ENSP00000349790.6 P20849-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152068
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000208
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000798
AC:
2
AN:
250718
AF XY:
0.0000147
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:
0.0000462
Gnomad NFE exome
AF:
0.00000884
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1461862
Hom.:
0
Cov.:
31
AF XY:
0.0000261
AC XY:
19
AN XY:
727224
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53406
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000279
AC:
31
AN:
1112006
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
Heterozygous variant carriers
0
3
6
10
13
16
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:
152186
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74406
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41522
American (AMR)
AF:
0.0000654
AC:
1
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.000208
AC:
1
AN:
4812
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
292
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67988
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

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

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Dec 17, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.2695G>A (p.G899S) alteration is located in exon 38 (coding exon 38) of the COL9A1 gene. This alteration results from a G to A substitution at nucleotide position 2695, causing the glycine (G) at amino acid position 899 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Oct 26, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals affected with COL9A1-related conditions. This variant is present in population databases (rs770502831, gnomAD 0.004%). This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 899 of the COL9A1 protein (p.Gly899Ser). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt COL9A1 protein function. 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
0.21
BayesDel_addAF
Pathogenic
0.54
D
BayesDel_noAF
Pathogenic
0.53
CADD
Pathogenic
31
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.67
D;.
Eigen
Pathogenic
0.84
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.94
D;D
M_CAP
Pathogenic
0.45
D
MetaRNN
Pathogenic
0.91
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.6
H;.
PhyloP100
5.0
PrimateAI
Uncertain
0.74
T
PROVEAN
Uncertain
-4.3
D;D
REVEL
Pathogenic
0.94
Sift
Pathogenic
0.0
D;D
Sift4G
Uncertain
0.022
D;D
Polyphen
1.0
D;D
Vest4
0.46
MutPred
0.87
Gain of glycosylation at G899 (P = 0.0181);.;
MVP
0.98
MPC
0.42
ClinPred
1.0
D
GERP RS
5.9
Varity_R
0.75
gMVP
0.95
Mutation Taster
=47/53
disease causing

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: rs770502831; hg19: chr6-70926671; API