2-227051141-C-T
Variant summary
Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM5PP3_StrongPP5
The NM_000092.5(COL4A4):c.2986G>A(p.Gly996Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000403 in 1,614,004 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G996W) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000092.5 missense
Scores
Clinical Significance
Conservation
Publications
- autosomal recessive Alport syndromeInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, Orphanet, Ambry Genetics, Myriad Women’s Health
- Alport syndromeInheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
- hematuria, benign familial, 1Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
- autosomal dominant Alport syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 7 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152150Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000281 AC: 7AN: 249466 AF XY: 0.0000222 show subpopulations
GnomAD4 exome AF: 0.0000404 AC: 59AN: 1461854Hom.: 0 Cov.: 34 AF XY: 0.0000385 AC XY: 28AN XY: 727226 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000394 AC: 6AN: 152150Hom.: 0 Cov.: 32 AF XY: 0.0000538 AC XY: 4AN XY: 74322 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Benign familial hematuria Pathogenic:2
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not provided Uncertain:2
This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 996 of the COL4A4 protein (p.Gly996Arg). This variant is present in population databases (rs370474706, gnomAD 0.008%). This missense change has been observed in individual(s) with hematuria and/or proteinuria (PMID: 26934356, 32647767). ClinVar contains an entry for this variant (Variation ID: 222055). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt COL4A4 protein function with a positive predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Reported in an individual with hematuria in published literature, however, renal and hearing loss evaluations were not performed on this child (PMID: 26934356); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Affects a glycine residue in a Gly-X-Y motif in the triple helical region of the COL4A4 gene; This variant is associated with the following publications: (PMID: 32647767, 34426522, 26934356) -
Autosomal recessive Alport syndrome;CN376803:Hematuria, benign familial, 1 Pathogenic:1
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COL4A4-related disorder Pathogenic:1
The COL4A4 c.2986G>A variant is predicted to result in the amino acid substitution p.Gly996Arg. This variant has been reported in at least two patients with Alport syndrome and IgA related neuropathy (Kovács et al. 2016. PubMed ID: 26934356; Li et al. 2020. PubMed ID: 2647767). This variant is reported in 0.0070% of alleles in individuals of European (Non-Finnish) descent in gnomAD. The p.Gly996Arg variant affects a Gly residue of the conserved triple helical domain (residues 65 – 1459) of the COL4A4 protein (uniprot.org). The majority of pathogenic variants in COL4A4 substitute a glycine residue to a bulkier amino acid in the triple-helical domain (Hudson et al. 1993. PubMed ID: 8253711; https://www.ncbi.nlm.nih.gov/books/NBK1207/). This variant is interpreted as pathogenic. -
Alport syndrome Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at