NM_001845.6:c.3949+48T>A

Variant names:

• chr13-110167110-A-T
• rs652572
• NM_001845.6:c.3949+48T>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001845.6(COL4A1):​c.3949+48T>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000066 in 151,520 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.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: COL4A1 NM_001845.6 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0210
• Publications: 11 publications found

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]

COL4A1 Gene-Disease associations (from GenCC):

• brain small vessel disease 1 with or without ocular anomalies

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: G2P, Ambry Genetics, PanelApp Australia, Orphanet, Genomics England PanelApp
• autosomal dominant familial hematuria-retinal arteriolar tortuosity-contractures syndrome

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Ambry Genetics
• microangiopathy and leukoencephalopathy, pontine, autosomal dominant

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• familial porencephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• pontine autosomal dominant microangiopathy with leukoencephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinal arterial tortuosity

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• muscular dystrophy-dystroglycanopathy, type A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.86).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL4A1	NM_001845.6	c.3949+48T>A		intron_variant	Intron 44 of 51	ENST00000375820.10	NP_001836.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL4A1	ENST00000375820.10	c.3949+48T>A		intron_variant	Intron 44 of 51	1	NM_001845.6	ENSP00000364979.4

Frequencies

GnomAD3 genomes AF: 0.00000660 AC: 1 AN: 151520 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000195

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1356672 Hom.: 0 Cov.: 21 AF XY: 0.00 AC XY: 0 AN XY: 681084

African (AFR) AF: 0.00 AC: 0 AN: 31498

American (AMR) AF: 0.00 AC: 0 AN: 44572

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25496

East Asian (EAS) AF: 0.00 AC: 0 AN: 39202

South Asian (SAS) AF: 0.00 AC: 0 AN: 84100

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53316

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5336

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1016218

Other (OTH) AF: 0.00 AC: 0 AN: 56934

GnomAD4 genome AF: 0.00000660 AC: 1 AN: 151520 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 73982

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41252

American (AMR) AF: 0.00 AC: 0 AN: 15234

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.000195 AC: 1 AN: 5126

South Asian (SAS) AF: 0.00 AC: 0 AN: 4814

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10502

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 310

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67818

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 8460

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
CADD	Benign	2.5
DANN	Benign	0.66
PhyloP100		-0.021

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

Other links and lift over

dbSNP: rs652572; hg19: chr13-110819457;