NM_001379500.1:c.2158-9C>T

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2

The NM_001379500.1(COL18A1):​c.2158-9C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00119 in 1,613,404 control chromosomes in the GnomAD database, including 8 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00081 ( 2 hom., cov: 33)
Exomes 𝑓: 0.0012 ( 6 hom. )

Consequence

COL18A1
NM_001379500.1 intron

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:2

Conservation

PhyloP100: -1.85

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: 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 -9 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.96).
BP6
Variant 21-45492526-C-T is Benign according to our data. Variant chr21-45492526-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 447118.
BS2
High Homozygotes in GnomAd4 at 2 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL18A1NM_001379500.1 linkc.2158-9C>T intron_variant Intron 22 of 41 ENST00000651438.1 NP_001366429.1
COL18A1NM_130444.3 linkc.3403-9C>T intron_variant Intron 21 of 40 NP_569711.2 P39060
COL18A1NM_030582.4 linkc.2698-9C>T intron_variant Intron 21 of 40 NP_085059.2 P39060D3DSM5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL18A1ENST00000651438.1 linkc.2158-9C>T intron_variant Intron 22 of 41 NM_001379500.1 ENSP00000498485.1 P39060-2
COL18A1ENST00000355480.10 linkc.2698-9C>T intron_variant Intron 21 of 40 1 ENSP00000347665.5 P39060-1
COL18A1ENST00000359759.8 linkc.3403-9C>T intron_variant Intron 21 of 40 5 ENSP00000352798.4 P39060-3
COL18A1ENST00000342220.9 linkc.199-9C>T intron_variant Intron 3 of 22 2 ENSP00000339118.5 H7BXV5

Frequencies

GnomAD3 genomes
AF:
0.000815
AC:
124
AN:
152186
Hom.:
2
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000169
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00111
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.00187
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00131
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000822
AC:
205
AN:
249252
AF XY:
0.000842
show subpopulations
Gnomad AFR exome
AF:
0.000194
Gnomad AMR exome
AF:
0.000898
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000111
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00117
Gnomad OTH exome
AF:
0.000330
GnomAD4 exome
AF:
0.00123
AC:
1796
AN:
1461100
Hom.:
6
Cov.:
34
AF XY:
0.00125
AC XY:
910
AN XY:
726830
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33478
American (AMR)
AF:
0.000738
AC:
33
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26136
East Asian (EAS)
AF:
0.0000756
AC:
3
AN:
39700
South Asian (SAS)
AF:
0.00152
AC:
131
AN:
86258
European-Finnish (FIN)
AF:
0.0000190
AC:
1
AN:
52710
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00137
AC:
1527
AN:
1111950
Other (OTH)
AF:
0.00162
AC:
98
AN:
60376
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.459
Heterozygous variant carriers
0
104
208
313
417
521
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
60
120
180
240
300
<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:
0.000814
AC:
124
AN:
152304
Hom.:
2
Cov.:
33
AF XY:
0.000725
AC XY:
54
AN XY:
74472
show subpopulations
African (AFR)
AF:
0.000168
AC:
7
AN:
41572
American (AMR)
AF:
0.00111
AC:
17
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5178
South Asian (SAS)
AF:
0.00187
AC:
9
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00131
AC:
89
AN:
68012
Other (OTH)
AF:
0.000473
AC:
1
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
Heterozygous variant carriers
0
6
12
17
23
29
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:
0.000975
Hom.:
1
Bravo
AF:
0.000820
EpiCase
AF:
0.00164
EpiControl
AF:
0.00184

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Knobloch syndrome Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not specified Benign:1
Dec 01, 2016
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
Jan 28, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.96
CADD
Benign
0.75
DANN
Benign
0.82
PhyloP100
-1.8
RBP_binding_hub_radar
0.85
RBP_regulation_power_radar
2.0
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: rs200143450; hg19: chr21-46912440; COSMIC: COSV60592960; COSMIC: COSV60592960; API