rs368594049

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_StrongBP6_Very_Strong

The NM_001379500.1(COL18A1):​c.1254C>T​(p.Asp418Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000183 in 1,613,670 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.0011 ( 1 hom., cov: 31)
Exomes 𝑓: 0.000089 ( 0 hom. )

Consequence

COL18A1
NM_001379500.1 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: -2.10

Publications

1 publications found
Variant links:
Genes affected
COL18A1 (HGNC:2195): (collagen type XVIII alpha 1 chain) This gene encodes the alpha chain of type XVIII collagen. This collagen is one of the multiplexins, extracellular matrix proteins that contain multiple triple-helix domains (collagenous domains) interrupted by non-collagenous domains. A long isoform of the protein has an N-terminal domain that is homologous to the extracellular part of frizzled receptors. Proteolytic processing at several endogenous cleavage sites in the C-terminal domain results in production of endostatin, a potent antiangiogenic protein that is able to inhibit angiogenesis and tumor growth. Mutations in this gene are associated with Knobloch syndrome. The main features of this syndrome involve retinal abnormalities, so type XVIII collagen may play an important role in retinal structure and in neural tube closure. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2014]
COL18A1 Gene-Disease associations (from GenCC):
  • Knobloch syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, G2P
  • Knobloch syndrome
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Orphanet
  • hereditary glaucoma, primary closed-angle
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -12 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.9).
BP6
Variant 21-45479907-C-T is Benign according to our data. Variant chr21-45479907-C-T is described in ClinVar as Benign. ClinVar VariationId is 447111.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL18A1NM_001379500.1 linkc.1254C>T p.Asp418Asp synonymous_variant Exon 10 of 42 ENST00000651438.1 NP_001366429.1
COL18A1NM_130444.3 linkc.2499C>T p.Asp833Asp synonymous_variant Exon 9 of 41 NP_569711.2 P39060
COL18A1NM_030582.4 linkc.1794C>T p.Asp598Asp synonymous_variant Exon 9 of 41 NP_085059.2 P39060D3DSM5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL18A1ENST00000651438.1 linkc.1254C>T p.Asp418Asp synonymous_variant Exon 10 of 42 NM_001379500.1 ENSP00000498485.1 P39060-2
COL18A1ENST00000355480.10 linkc.1794C>T p.Asp598Asp synonymous_variant Exon 9 of 41 1 ENSP00000347665.5 P39060-1
COL18A1ENST00000359759.8 linkc.2499C>T p.Asp833Asp synonymous_variant Exon 9 of 41 5 ENSP00000352798.4 P39060-3

Frequencies

GnomAD3 genomes
AF:
0.00109
AC:
165
AN:
151954
Hom.:
1
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00380
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000393
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:
0.00
Gnomad OTH
AF:
0.000958
GnomAD2 exomes
AF:
0.000257
AC:
64
AN:
248826
AF XY:
0.000170
show subpopulations
Gnomad AFR exome
AF:
0.00383
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000887
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000889
AC:
130
AN:
1461598
Hom.:
0
Cov.:
33
AF XY:
0.0000811
AC XY:
59
AN XY:
727140
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00329
AC:
110
AN:
33456
American (AMR)
AF:
0.000112
AC:
5
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53186
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5764
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111990
Other (OTH)
AF:
0.000215
AC:
13
AN:
60388
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.382
Heterozygous variant carriers
0
5
10
16
21
26
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.00109
AC:
166
AN:
152072
Hom.:
1
Cov.:
31
AF XY:
0.000901
AC XY:
67
AN XY:
74352
show subpopulations
African (AFR)
AF:
0.00381
AC:
158
AN:
41478
American (AMR)
AF:
0.000392
AC:
6
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5146
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4808
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10594
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67964
Other (OTH)
AF:
0.000948
AC:
2
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.518
Heterozygous variant carriers
0
9
18
28
37
46
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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:
0.000461
Hom.:
0
Bravo
AF:
0.00127
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

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

Submissions by phenotype

not specified Benign:1
Feb 03, 2017
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
Feb 02, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

COL18A1-related disorder Benign:1
Jun 15, 2019
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.90
CADD
Benign
1.2
DANN
Benign
0.43
PhyloP100
-2.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Mutation Taster
=100/0
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: rs368594049; hg19: chr21-46899821; API