chr21-45487424-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001379500.1(COL18A1):​c.1834-23C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000931 in 1,611,412 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. There are indicators that this mutation may affect the branch point..

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

COL18A1
NM_001379500.1 intron

Scores

2

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -3.20
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BP4
This place is a probable branch point but likely benign (scored 1 / 10). Computational evidence support a benign effect (BayesDel_noAF=-0.94).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
COL18A1NM_001379500.1 linkuse as main transcriptc.1834-23C>T intron_variant ENST00000651438.1
COL18A1NM_030582.4 linkuse as main transcriptc.2374-23C>T intron_variant
COL18A1NM_130444.3 linkuse as main transcriptc.3079-23C>T intron_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
COL18A1ENST00000651438.1 linkuse as main transcriptc.1834-23C>T intron_variant NM_001379500.1 P39060-2
COL18A1ENST00000355480.10 linkuse as main transcriptc.2374-23C>T intron_variant 1 P39060-1
COL18A1ENST00000359759.8 linkuse as main transcriptc.3079-23C>T intron_variant 5 P1P39060-3

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152154
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000121
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:
0.0000941
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000161
AC:
4
AN:
247794
Hom.:
0
AF XY:
0.00000742
AC XY:
1
AN XY:
134728
show subpopulations
Gnomad AFR exome
AF:
0.0000651
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000482
Gnomad NFE exome
AF:
0.00000888
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000617
AC:
9
AN:
1459258
Hom.:
0
Cov.:
33
AF XY:
0.00000551
AC XY:
4
AN XY:
725948
show subpopulations
Gnomad4 AFR exome
AF:
0.0000896
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.0000193
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152154
Hom.:
0
Cov.:
33
AF XY:
0.0000673
AC XY:
5
AN XY:
74324
show subpopulations
Gnomad4 AFR
AF:
0.000121
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.0000941
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.94
CADD
Benign
0.19
DANN
Benign
0.66
BranchPoint Hunter
1.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs73370824; hg19: chr21-46907338; API