21-45492695-G-A

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP6_Very_StrongBS1BS2

The NM_001379500.1(COL18A1):​c.2196G>A​(p.Pro732Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0016 in 1,610,176 control chromosomes in the GnomAD database, including 34 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.0085 ( 22 hom., cov: 33)
Exomes 𝑓: 0.00088 ( 12 hom. )

Consequence

COL18A1
NM_001379500.1 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: -2.60

Publications

0 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: ClinGen, G2P, Labcorp Genetics (formerly Invitae)
  • 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 -16 ACMG points.

BP6
Variant 21-45492695-G-A is Benign according to our data. Variant chr21-45492695-G-A is described in ClinVar as Benign. ClinVar VariationId is 261899.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00852 (1296/152200) while in subpopulation AFR AF = 0.0296 (1227/41502). AF 95% confidence interval is 0.0282. There are 22 homozygotes in GnomAd4. There are 628 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 22 AD,AR gene

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

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL18A1
NM_001379500.1
MANE Select
c.2196G>Ap.Pro732Pro
synonymous
Exon 24 of 42NP_001366429.1P39060-2
COL18A1
NM_130444.3
c.3441G>Ap.Pro1147Pro
synonymous
Exon 23 of 41NP_569711.2
COL18A1
NM_030582.4
c.2736G>Ap.Pro912Pro
synonymous
Exon 23 of 41NP_085059.2A0AAG2UXZ5

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
COL18A1
ENST00000651438.1
MANE Select
c.2196G>Ap.Pro732Pro
synonymous
Exon 24 of 42ENSP00000498485.1P39060-2
COL18A1
ENST00000355480.10
TSL:1
c.2736G>Ap.Pro912Pro
synonymous
Exon 23 of 41ENSP00000347665.5P39060-1
COL18A1
ENST00000359759.8
TSL:5
c.3441G>Ap.Pro1147Pro
synonymous
Exon 23 of 41ENSP00000352798.4P39060-3

Frequencies

GnomAD3 genomes
AF:
0.00851
AC:
1294
AN:
152082
Hom.:
22
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0296
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00288
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00633
Gnomad NFE
AF:
0.000132
Gnomad OTH
AF:
0.00670
GnomAD2 exomes
AF:
0.00230
AC:
563
AN:
245038
AF XY:
0.00173
show subpopulations
Gnomad AFR exome
AF:
0.0321
Gnomad AMR exome
AF:
0.00157
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000153
Gnomad OTH exome
AF:
0.00117
GnomAD4 exome
AF:
0.000876
AC:
1277
AN:
1457976
Hom.:
12
Cov.:
33
AF XY:
0.000776
AC XY:
563
AN XY:
725462
show subpopulations
African (AFR)
AF:
0.0294
AC:
984
AN:
33430
American (AMR)
AF:
0.00154
AC:
69
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86228
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50818
Middle Eastern (MID)
AF:
0.00218
AC:
12
AN:
5508
European-Non Finnish (NFE)
AF:
0.0000828
AC:
92
AN:
1111192
Other (OTH)
AF:
0.00197
AC:
119
AN:
60284
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
74
147
221
294
368
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
30
60
90
120
150
<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:
0.00852
AC:
1296
AN:
152200
Hom.:
22
Cov.:
33
AF XY:
0.00844
AC XY:
628
AN XY:
74390
show subpopulations
African (AFR)
AF:
0.0296
AC:
1227
AN:
41502
American (AMR)
AF:
0.00288
AC:
44
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5160
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10596
Middle Eastern (MID)
AF:
0.00680
AC:
2
AN:
294
European-Non Finnish (NFE)
AF:
0.000132
AC:
9
AN:
68022
Other (OTH)
AF:
0.00663
AC:
14
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.499
Heterozygous variant carriers
0
62
123
185
246
308
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
20
40
60
80
100
<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:
0.00434
Hom.:
8
Bravo
AF:
0.00989
Asia WGS
AF:
0.00202
AC:
7
AN:
3478
EpiCase
AF:
0.000218
EpiControl
AF:
0.000237

ClinVar

ClinVar submissions
Significance:Benign
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
2
not provided (2)
-
-
1
Knobloch syndrome (1)
-
-
1
not specified (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.95
CADD
Benign
1.5
DANN
Benign
0.77
PhyloP100
-2.6
RBP_binding_hub_radar
1.1
RBP_regulation_power_radar
2.9
Mutation Taster
=98/2
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.22
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.22
Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs115470104; hg19: chr21-46912609; API