chr2-227310813-T-G
Variant summary
Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PP3_ModeratePP5_Very_Strong
The NM_000091.5(COL4A3):c.4793T>G(p.Leu1598Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000223 in 1,614,168 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 Likely pathogenic (★★).
Frequency
Consequence
NM_000091.5 missense
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Pathogenic. The variant received 10 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| COL4A3 | NM_000091.5 | c.4793T>G | p.Leu1598Arg | missense_variant | Exon 51 of 52 | ENST00000396578.8 | NP_000082.2 | |
| COL4A3 | XM_005246277.4 | c.4688T>G | p.Leu1563Arg | missense_variant | Exon 50 of 51 | XP_005246334.1 | ||
| COL4A3 | XM_011510555.2 | c.4780T>G | p.Trp1594Gly | missense_variant | Exon 51 of 51 | XP_011508857.1 | ||
| MFF-DT | NR_102371.1 | n.48-5158A>C | intron_variant | Intron 1 of 13 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000328 AC: 5AN: 152224Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000561 AC: 14AN: 249436 AF XY: 0.0000443 show subpopulations
GnomAD4 exome AF: 0.0000212 AC: 31AN: 1461826Hom.: 0 Cov.: 32 AF XY: 0.0000165 AC XY: 12AN XY: 727218 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000328 AC: 5AN: 152342Hom.: 0 Cov.: 33 AF XY: 0.0000268 AC XY: 2AN XY: 74514 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Autosomal recessive Alport syndrome Pathogenic:3Uncertain:1
PM1:Located in a mutational hot spot PM2:not found in gnomAD PP3:Multiple lines of computational evidence support a deleterious effect on the gene or gene product -
This submission and the accompanying classification are no longer maintained by the submitter.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. -
Variant summary: COL4A3 c.4793T>G (p.Leu1598Arg) results in a non-conservative amino acid change located in the Collagen IV, non-collagenous domain (IPR001442) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. At least one publication reports experimental evidence that this variant affects mRNA splicing (Deng_2022). The variant allele was found at a frequency of 5.6e-05 in 249436 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in COL4A3 causing Alport Syndrome, Autosomal Recessive (5.6e-05 vs 0.0014), allowing no conclusion about variant significance. c.4793T>G has been reported in the literature in multiple individuals affected with Alport Syndrome, Autosomal Recessive (e.g., Oka_2014, Zhang_2021). These data indicate that the variant is very likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 24633401, 33772369, 35386907). ClinVar contains an entry for this variant (Variation ID: 550745). Based on the evidence outlined above, the variant was classified as pathogenic. -
Based on the classification scheme VCGS_Germline_v1.3.3, this variant is classified as Pathogenic. Following criteria are met: 0103 - Dominant negative, caused by missense variants mostly glycine substitutions that affect the conformation of the protein, and loss of function, caused by either protein truncating and missense variants, are known mechanisms of disease in this gene and are associated with Alport syndrome and thin basement membrane nephropathy (PMID: 12028435, OMIM). (I) 0108 - This gene is associated with both recessive (Alport syndrome) and dominant disease (Alport syndrome and thin basement membrane nephropathy) (OMIM). (I) 0200 - Variant is predicted to result in a missense amino acid change from leucine to arginine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD v2 <0.01, East Asian subpopulation (15 heterozygotes, 0 homozygotes). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated C4 domain (NCBI, PDB). (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been previously reported as pathogenic in patients with autosomal recessive Alport syndrome (ClinVar, PMID: 24633401). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Alport syndrome 3b, autosomal recessive Pathogenic:1
The variant is observed at an extremely low frequency in the gnomAD v4.0.0 dataset (total allele frequency: 0.002%). Predicted Consequence/Location: Missense variant In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.98 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.77 (>=0.6, sensitivity 0.72 and precision 0.9)]. The same nucleotide change resulting in the same amino acid change has been previously reported to be associated with COL4A3 related disorder (ClinVar ID: VCV000550745 /PMID: 24633401 /3billion dataset).The variant has been reported to be in trans with a pathogenic variant as either compound heterozygous or homozygous in at least 2 similarly affected unrelated individuals (PMID: 24633401). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -
Hematuria, benign familial, 2;C5882663:Autosomal dominant Alport syndrome;C5882699:Alport syndrome 3b, autosomal recessive Pathogenic:1
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Autosomal dominant Alport syndrome;C5882699:Alport syndrome 3b, autosomal recessive Pathogenic:1
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not provided Pathogenic:1
This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 1598 of the COL4A3 protein (p.Leu1598Arg). This variant is present in population databases (rs752452590, gnomAD 0.08%). This missense change has been observed in individual(s) with COL4A3-related conditions (PMID: 24633401). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 550745). 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 COL4A3 protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at