chr2-227237970-TTG-T

Position:

• chr2-227237970-TTG-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000091.5(COL4A3):​c.94_95del​(p.Val32LeufsTer2) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL4A3 NM_000091.5 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.66

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)

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 198 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-227237970-TTG-T is Pathogenic according to our data. Variant chr2-227237970-TTG-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1725980.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL4A3	NM_000091.5	c.94_95del	p.Val32LeufsTer2	frameshift_variant	2/52	ENST00000396578.8	NP_000082.2
MFF-DT	NR_102371.1	n.1681+114_1681+115del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL4A3	ENST00000396578.8	c.94_95del	p.Val32LeufsTer2	frameshift_variant	2/52	1	NM_000091.5	ENSP00000379823	P1
MFF-DT	ENST00000439598.6	n.1681+114_1681+115del		intron_variant, non_coding_transcript_variant		1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal recessive Alport syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Apr 29, 2022

NM_000091.4(COL4A3):c.94_95delGT(V32Lfs*2) is expected to be pathogenic in the context of COL4A3-related Alport syndrome. This variant is predicted to lead to an abnormal or absent protein product due to the creation of a premature termination codon in COL4A3, a gene where loss-of-function variants are known to be pathogenic. Please note: this variant was assessed in the context of healthy population screening. -

Computational scores

Source: dbNSFP v4.3

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-228102686;