21-45504431-C-T

Position:

chr21-45504431-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_001379500.1(COL18A1):c.2743C>T(p.Arg915Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000621 in 1,611,410 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

COL18A1
NM_001379500.1 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: -0.448

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 links:

SLC19A1 (HGNC:10937): (solute carrier family 19 member 1) The membrane protein encoded by this gene is a transporter of folate and is involved in the regulation of intracellular concentrations of folate. Three transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Mar 2011]

SLC19A1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PP5

Variant 21-45504431-C-T is Pathogenic according to our data. Variant chr21-45504431-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 191317.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr21-45504431-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL18A1	NM_001379500.1 linkuse as main transcript	c.2743C>T	p.Arg915Ter	stop_gained	34/42	ENST00000651438.1	NP_001366429.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL18A1	ENST00000651438.1 linkuse as main transcript	c.2743C>T	p.Arg915Ter	stop_gained	34/42		NM_001379500.1	ENSP00000498485		P39060-2

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152082

Hom.:

Cov.:

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000617

AC:

AN:

1459328

Hom.:

Cov.:

AF XY:

0.00000964

AC XY:

AN XY:

725962

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000384

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.0000192

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152082

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74284

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

ExAC

AF:

0.00000838

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jan 01, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Sep 05, 2019	- -
Likely pathogenic, criteria provided, single submitter	research	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 23, 2023	This sequence change creates a premature translational stop signal (p.Arg915*) in the COL18A1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in COL18A1 are known to be pathogenic (PMID: 12415512, 25456301). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Knobloch syndrome (PMID: 21862674). ClinVar contains an entry for this variant (Variation ID: 191317). For these reasons, this variant has been classified as Pathogenic. -

Knobloch syndrome 1

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Juno Genomics, Hangzhou Juno Genomics, Inc

PVS1+PM2_Supporting+PM3+PP4 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.28

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Benign

-0.12

Eigen_PC

Benign

-0.44

FATHMM_MKL

Benign

0.080

MutationTaster

Benign

1.0

A;A;A;N

Vest4

0.83

GERP RS

2.2

RBP_binding_hub_radar

1.0

RBP_regulation_power_radar

2.8

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.13

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over