chr21-45504028-TTTC-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -15 ACMG points: 1P and 16B. PM4_SupportingBP6_Very_StrongBS1BS2

The NM_001379500.1(COL18A1):c.2705_2707delTTC(p.Leu902del) variant causes a disruptive inframe deletion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000889 in 1,613,688 control chromosomes in the GnomAD database, including 8 homozygotes. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0047 ( 4 hom., cov: 32)

Exomes 𝑓: 0.00049 ( 4 hom. )

Consequence

COL18A1
NM_001379500.1 disruptive_inframe_deletion

Scores

Not classified

Clinical Significance

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

Conservation

PhyloP100: 3.29

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 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 was made for transcript

Our verdict: Benign. The variant received -15 ACMG points.

PM4

Nonframeshift variant in NON repetitive region in NM_001379500.1. Strenght limited to Supporting due to length of the change: 1aa.

BP6

Variant 21-45504028-TTTC-T is Benign according to our data. Variant chr21-45504028-TTTC-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 445973.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 = 0.00469 (714/152280) while in subpopulation AFR AF = 0.0165 (684/41568). AF 95% confidence interval is 0.0154. There are 4 homozygotes in GnomAd4. There are 332 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High Homozygotes in GnomAd4 at 4 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL18A1	NM_001379500.1 link	c.2705_2707delTTC	p.Leu902del	disruptive_inframe_deletion	Exon 33 of 42	ENST00000651438.1	NP_001366429.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL18A1	ENST00000651438.1 link	c.2705_2707delTTC	p.Leu902del	disruptive_inframe_deletion	Exon 33 of 42		NM_001379500.1	ENSP00000498485.1

Frequencies

GnomAD3 genomes

AF:

0.00470

AC:

715

AN:

152162

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0165

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00124

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.0000882

Gnomad OTH

AF:

0.00191

GnomAD2 exomes

AF:

0.00116

AC:

288

AN:

248700

AF XY:

0.000939

show subpopulations

Gnomad AFR exome

AF:

0.0165

Gnomad AMR exome

AF:

0.000522

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000133

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.000493

AC:

721

AN:

1461408

Hom.:

AF XY:

0.000462

AC XY:

336

AN XY:

726988

show subpopulations

African (AFR)

AF:

0.0158

AC:

530

AN:

33480

American (AMR)

AF:

0.000604

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53008

Middle Eastern (MID)

AF:

0.000520

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.0000728

AC:

AN:

1111960

Other (OTH)

AF:

0.00129

AC:

AN:

60380

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.452

Heterozygous variant carriers

122

162

203

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

100

<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:

0.00469

AC:

714

AN:

152280

Hom.:

Cov.:

AF XY:

0.00446

AC XY:

332

AN XY:

74470

show subpopulations

African (AFR)

AF:

0.0165

AC:

684

AN:

41568

American (AMR)

AF:

0.00124

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5164

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00340

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000882

AC:

AN:

68016

Other (OTH)

AF:

0.00189

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

Heterozygous variant carriers

106

141

176

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

Variant carriers

<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:

0.00273

Hom.:

Bravo

AF:

0.00546

Asia WGS

AF:

0.000866

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:2

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 15, 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

- -

not specified

Benign:1

Jul 22, 2019

Genetic Services Laboratory, University of Chicago

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Knobloch syndrome 1;C5394374:Hereditary glaucoma, primary closed-angle

Benign:1

Nov 05, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

3.3

Mutation Taster

=77/23

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

Details are displayed if max score is > 0.2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over