rs1445615417

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000091.5(COL4A3):​c.4420_4424delCTTTT​(p.Leu1474CysfsTer34) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,996 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

COL4A3
NM_000091.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 7.67

Publications

0 publications found
Variant links:
Genes affected
COL4A3 (HGNC:2204): (collagen type IV alpha 3 chain) Type IV collagen, the major structural component of basement membranes, is a multimeric protein composed of 3 alpha subunits. These subunits are encoded by 6 different genes, alpha 1 through alpha 6, each of which can form a triple helix structure with 2 other subunits to form type IV collagen. This gene encodes alpha 3. In the Goodpasture syndrome, autoantibodies bind to the collagen molecules in the basement membranes of alveoli and glomeruli. The epitopes that elicit these autoantibodies are localized largely to the non-collagenous C-terminal domain of the protein. A specific kinase phosphorylates amino acids in this same C-terminal region and the expression of this kinase is upregulated during pathogenesis. This gene is also linked to an autosomal recessive form of Alport syndrome. The mutations contributing to this syndrome are also located within the exons that encode this C-terminal region. Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter. [provided by RefSeq, Jun 2010]
MFF-DT (HGNC:41067): (MFF divergent transcript)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 2-227307867-GTTTTC-G is Pathogenic according to our data. Variant chr2-227307867-GTTTTC-G is described in ClinVar as Pathogenic. ClinVar VariationId is 556032.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL4A3NM_000091.5 linkc.4420_4424delCTTTT p.Leu1474CysfsTer34 frameshift_variant Exon 48 of 52 ENST00000396578.8 NP_000082.2 Q01955-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL4A3ENST00000396578.8 linkc.4420_4424delCTTTT p.Leu1474CysfsTer34 frameshift_variant Exon 48 of 52 1 NM_000091.5 ENSP00000379823.3 Q01955-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152116
Hom.:
0
Cov.:
32
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000410
AC:
6
AN:
1461880
Hom.:
0
AF XY:
0.00000550
AC XY:
4
AN XY:
727240
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1112004
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00206180), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152116
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74296
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41412
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10600
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.600
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive Alport syndrome Pathogenic:3
Jan 01, 1997
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Oct 12, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: COL4A3 c.4420_4424delCTTTT (p.Leu1474CysfsX34) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 249424 control chromosomes (gnomAD). c.4420_4424delCTTTT has been reported in the literature in individuals affected with Alport Syndrome, Autosomal Recessive (Mochizuki_1994, Moriniere_2014). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One ClinVar submitter (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Jan 09, 2018
Counsyl
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

not provided Pathogenic:1
Nov 03, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Leu1474Cysfs*34) in the COL4A3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in COL4A3 are known to be pathogenic (PMID: 8956999, 24854265, 26809805, 27281700). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with autosomal dominant and autosomal recessive Alport syndrome (PMID: 7987301, 7987396). This variant is also known as a 5bp CTTTT deletion. ClinVar contains an entry for this variant (Variation ID: 556032). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
7.7
Mutation Taster
=4/196
disease causing (ClinVar)

Splicing

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

Publications

Other links and lift over

dbSNP: rs1445615417; hg19: chr2-228172583; API