rs7277693

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The ENST00000355480.10(COL18A1):​c.56C>T​(p.Ala19Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00112 in 1,613,930 control chromosomes in the GnomAD database, including 23 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. A19A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0060 ( 14 hom., cov: 34)
Exomes 𝑓: 0.00062 ( 9 hom. )

Consequence

COL18A1
ENST00000355480.10 missense

Scores

1
16

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: -2.00

Publications

2 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 -20 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.003536135).
BP6
Variant 21-45455586-C-T is Benign according to our data. Variant chr21-45455586-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 445614.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 = 0.00597 (910/152356) while in subpopulation AFR AF = 0.0206 (855/41576). AF 95% confidence interval is 0.0194. There are 14 homozygotes in GnomAd4. There are 405 alleles in the male GnomAd4 subpopulation. Median coverage is 34. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 14 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL18A1NM_001379500.1 linkc.107-12656C>T intron_variant Intron 2 of 41 ENST00000651438.1 NP_001366429.1
COL18A1NM_130444.3 linkc.56C>T p.Ala19Val missense_variant Exon 1 of 41 NP_569711.2 P39060
COL18A1NM_030582.4 linkc.56C>T p.Ala19Val missense_variant Exon 1 of 41 NP_085059.2 P39060D3DSM5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL18A1ENST00000355480.10 linkc.56C>T p.Ala19Val missense_variant Exon 1 of 41 1 ENSP00000347665.5 P39060-1
COL18A1ENST00000651438.1 linkc.107-12656C>T intron_variant Intron 2 of 41 NM_001379500.1 ENSP00000498485.1 P39060-2
COL18A1ENST00000359759.8 linkc.56C>T p.Ala19Val missense_variant Exon 1 of 41 5 ENSP00000352798.4 P39060-3

Frequencies

GnomAD3 genomes
AF:
0.00592
AC:
902
AN:
152238
Hom.:
14
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0204
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00268
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00316
Gnomad NFE
AF:
0.0000882
Gnomad OTH
AF:
0.00334
GnomAD2 exomes
AF:
0.00139
AC:
347
AN:
249084
AF XY:
0.00105
show subpopulations
Gnomad AFR exome
AF:
0.0198
Gnomad AMR exome
AF:
0.000898
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000708
Gnomad OTH exome
AF:
0.000496
GnomAD4 exome
AF:
0.000616
AC:
901
AN:
1461574
Hom.:
9
Cov.:
31
AF XY:
0.000512
AC XY:
372
AN XY:
727104
show subpopulations
African (AFR)
AF:
0.0220
AC:
737
AN:
33480
American (AMR)
AF:
0.00101
AC:
45
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000696
AC:
6
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53150
Middle Eastern (MID)
AF:
0.000521
AC:
3
AN:
5760
European-Non Finnish (NFE)
AF:
0.0000225
AC:
25
AN:
1111986
Other (OTH)
AF:
0.00141
AC:
85
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
61
121
182
242
303
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
26
52
78
104
130
<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:
0.00597
AC:
910
AN:
152356
Hom.:
14
Cov.:
34
AF XY:
0.00544
AC XY:
405
AN XY:
74498
show subpopulations
African (AFR)
AF:
0.0206
AC:
855
AN:
41576
American (AMR)
AF:
0.00268
AC:
41
AN:
15314
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:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.0000882
AC:
6
AN:
68034
Other (OTH)
AF:
0.00331
AC:
7
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.493
Heterozygous variant carriers
0
44
89
133
178
222
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
10
20
30
40
50
<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:
0.00224
Hom.:
4
Bravo
AF:
0.00666
ESP6500AA
AF:
0.0163
AC:
68
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.00169
AC:
204
Asia WGS
AF:
0.00144
AC:
5
AN:
3478
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:3
Mar 10, 2017
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Feb 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Benign:1
Jun 27, 2017
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.71
T
BayesDel_noAF
Benign
-0.78
CADD
Benign
1.9
DANN
Benign
0.52
DEOGEN2
Benign
0.037
.;T
Eigen
Benign
-1.5
Eigen_PC
Benign
-1.5
FATHMM_MKL
Benign
0.030
N
LIST_S2
Benign
0.35
T;T
MetaRNN
Benign
0.0035
T;T
MetaSVM
Benign
-1.0
T
PhyloP100
-2.0
PrimateAI
Benign
0.42
T
PROVEAN
Benign
-0.91
N;N
REVEL
Benign
0.034
Sift
Uncertain
0.019
D;D
Sift4G
Benign
0.52
T;T
Polyphen
0.0010
B;B
Vest4
0.13
MVP
0.14
MPC
0.067
ClinPred
0.010
T
GERP RS
-0.95
PromoterAI
-0.046
Neutral
Varity_R
0.050
gMVP
0.055
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: rs7277693; hg19: chr21-46875500; API