chr13-110167238-C-T

Position:

• chr13-110167238-C-T

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BS1 BS2

The NM_001845.6(COL4A1):​c.3877-8G>A variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000294 in 1,609,528 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0014 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00017 (1 hom.)
• Consequence: COL4A1 NM_001845.6 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.0002264
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:6
• Conservation: PhyloP100: -0.706

Genes affected

COL4A1 (HGNC:2202): (collagen type IV alpha 1 chain) This gene encodes a type IV collagen alpha protein. Type IV collagen proteins are integral components of basement membranes. This gene shares a bidirectional promoter with a paralogous gene on the opposite strand. The protein consists of an amino-terminal 7S domain, a triple-helix forming collagenous domain, and a carboxy-terminal non-collagenous domain. It functions as part of a heterotrimer and interacts with other extracellular matrix components such as perlecans, proteoglycans, and laminins. In addition, proteolytic cleavage of the non-collagenous carboxy-terminal domain results in a biologically active fragment known as arresten, which has anti-angiogenic and tumor suppressor properties. Mutations in this gene cause porencephaly, cerebrovascular disease, and renal and muscular defects. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2014]

ACMG classification

Verdict is Benign. Variant got -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).
• BP6: Variant 13-110167238-C-T is Benign according to our data. Variant chr13-110167238-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 311034.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr13-110167238-C-T is described in Lovd as [Likely_benign].
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00144 (220/152258) while in subpopulation AFR AF= 0.00472 (196/41556). AF 95% confidence interval is 0.00418. There are 0 homozygotes in gnomad4. There are 107 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High AC in GnomAd4 at 220 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL4A1	NM_001845.6	c.3877-8G>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000375820.10	NP_001836.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL4A1	ENST00000375820.10	c.3877-8G>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_001845.6	ENSP00000364979	P1
COL4A1	ENST00000650424.1	c.33-8G>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant				ENSP00000497477

Frequencies

GnomAD3 genomes AF: 0.00145 AC: 220 AN: 152140 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00473

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00118

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: 0.00

Gnomad OTH AF: 0.00287

GnomAD3 exomes AF: 0.000470 AC: 118 AN: 251204 Hom.: 0 AF XY: 0.000361 AC XY: 49 AN XY: 135778

Gnomad AFR exome AF: 0.00591

Gnomad AMR exome AF: 0.000549

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000174 AC: 254 AN: 1457270 Hom.: 1 Cov.: 32 AF XY: 0.000153 AC XY: 111 AN XY: 725386

Gnomad4 AFR exome AF: 0.00512

Gnomad4 AMR exome AF: 0.000671

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000903

Gnomad4 OTH exome AF: 0.000664

GnomAD4 genome AF: 0.00144 AC: 220 AN: 152258 Hom.: 0 Cov.: 32 AF XY: 0.00144 AC XY: 107 AN XY: 74438

Gnomad4 AFR AF: 0.00472

Gnomad4 AMR AF: 0.00118

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00284

Alfa AF: 0.0000894 Hom.: 0

Bravo AF: 0.00166

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Brain small vessel disease 1 with or without ocular anomalies Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jun 14, 2016	- -
Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided Benign:2

Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2023	COL4A1: BP4, BS1 -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 21, 2024	- -

not specified Benign:1

Benign, criteria provided, single submitter

clinical testing

Athena Diagnostics

Nov 23, 2016

- -

Autosomal dominant familial hematuria-retinal arteriolar tortuosity-contractures syndrome Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	5.0
DANN	Benign	0.35

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00023
dbscSNV1_RF	Benign	0.14
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

LitVar

Other links and lift over

dbSNP: rs370539477; hg19: chr13-110819585;