rs775168204

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1PP5_Moderate

The NM_001379500.1(COL18A1):​c.2118delC​(p.Gly707AspfsTer17) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000621 in 1,611,236 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. P706P) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000026 ( 1 hom., cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

COL18A1
NM_001379500.1 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: -1.80

Publications

6 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: Pathogenic. The variant received 10 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 21-45491268-GC-G is Pathogenic according to our data. Variant chr21-45491268-GC-G is described in ClinVar as Pathogenic. ClinVar VariationId is 1416901.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001379500.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL18A1
NM_001379500.1
MANE Select
c.2118delCp.Gly707AspfsTer17
frameshift
Exon 22 of 42NP_001366429.1
COL18A1
NM_130444.3
c.3363delCp.Gly1122AspfsTer17
frameshift
Exon 21 of 41NP_569711.2
COL18A1
NM_030582.4
c.2658delCp.Gly887AspfsTer17
frameshift
Exon 21 of 41NP_085059.2

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL18A1
ENST00000651438.1
MANE Select
c.2118delCp.Gly707AspfsTer17
frameshift
Exon 22 of 42ENSP00000498485.1
COL18A1
ENST00000355480.10
TSL:1
c.2658delCp.Gly887AspfsTer17
frameshift
Exon 21 of 41ENSP00000347665.5
COL18A1
ENST00000359759.8
TSL:5
c.3363delCp.Gly1122AspfsTer17
frameshift
Exon 21 of 41ENSP00000352798.4

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152042
Hom.:
1
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:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000163
AC:
4
AN:
244716
AF XY:
0.0000299
show subpopulations
Gnomad AFR exome
AF:
0.0000672
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:
0.0000273
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000411
AC:
6
AN:
1459194
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
725964
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33456
American (AMR)
AF:
0.00
AC:
0
AN:
44702
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26104
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86148
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52056
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5750
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1111012
Other (OTH)
AF:
0.00
AC:
0
AN:
60282
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.0000263
AC:
4
AN:
152042
Hom.:
1
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74244
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41418
American (AMR)
AF:
0.00
AC:
0
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5172
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
67982
Other (OTH)
AF:
0.00
AC:
0
AN:
2078
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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
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:
0.00
Hom.:
0
Bravo
AF:
0.0000113
EpiCase
AF:
0.00
EpiControl
AF:
0.0000595

ClinVar

ClinVar submissions as Germline

Significance:Pathogenic
Revision:criteria provided, single submitter
View on ClinVar
Pathogenic
VUS
Benign
Condition
1
-
-
not provided (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
PhyloP100
-1.8
Mutation Taster
=4/196
disease causing (fs/PTC)

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: rs775168204; hg19: chr21-46911182; COSMIC: COSV60587380; COSMIC: COSV60587380; API