rs1556418210

chrX-108614929-G-A

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_033380.3(COL4A5):c.2414G>A(p.Gly805Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. G805G) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 22)
• Consequence: COL4A5 NM_033380.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 8.33

Genes affected

COL4A5 (HGNC:2207): (collagen type IV alpha 5 chain) This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. Mutations in this gene are associated with X-linked Alport syndrome, also known as hereditary nephritis. 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. Alternatively spliced transcript variants have been identified for this gene. [provided by RefSeq, Aug 2010]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 4 uncertain in NM_033380.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant X-108614929-G-A is Pathogenic according to our data. Variant chrX-108614929-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 447200.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A5	NM_033380.3	c.2414G>A	p.Gly805Glu	missense_variant	30/53	ENST00000328300.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A5	ENST00000328300.11	c.2414G>A	p.Gly805Glu	missense_variant	30/53	1	NM_033380.3
COL4A5	ENST00000483338.1	c.1238G>A	p.Gly413Glu	missense_variant	14/20	1
COL4A5	ENST00000361603.7	c.2414G>A	p.Gly805Glu	missense_variant	30/51	2		P1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	May 12, 2022	This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 805 of the COL4A5 protein (p.Gly805Glu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of Alport syndrome (Invitae). ClinVar contains an entry for this variant (Variation ID: 447200). 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 COL4A5 protein function. This variant disrupts the triple helix domain of COL4A5. Glycine residues within the Gly-Xaa-Yaa repeats of the triple helix domain are required for the structure and stability of fibrillar collagens (PMID: 7695699, 8218237, 19344236). In COL4A5, missense variants at these glycine residues are significantly enriched in individuals with disease (PMID: 23720012, 27627812) compared to the general population (ExAC). This variant disrupts the p.Gly805 amino acid residue in COL4A5. Other variant(s) that disrupt this residue have been observed in individuals with COL4A5-related conditions (PMID: 32405592), which suggests that this may be a clinically significant amino acid residue. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 05, 2018	The G805E variant in the COL4A5 gene has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The G805E variant occurs within the triple-helical region of the COL4A5 gene and replaces the Glycine in the canonical Gly-X-Y repeat (Uniprot). Variants in these Glycines result in poor winding of the collagen triple helix and a less functional protein. This variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The G805E variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species, and in silico analysis predicts this variant is probably damaging to the protein structure/function. Based on currently available evidence, we consider G805E to be pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Oct 31, 2016	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
Cadd	Pathogenic	26
Dann	Uncertain	0.99
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.85	D;T;D
M_CAP	Pathogenic	0.84	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	4.7	H;H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-5.8	D;D;.
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D;.
Sift4G	Pathogenic	0.0	D;D;.
Polyphen		1.0	.;D;D
Vest4		0.99
MutPred		1.0		Gain of solvent accessibility (P = 0.0638);Gain of solvent accessibility (P = 0.0638);.;
MVP		1.0
MPC		0.39
ClinPred		1.0	D
GERP RS		4.5
Varity_R		0.99
gMVP		1.0

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

LitVar

Other links and lift over

dbSNP: rs1556418210; hg19: chrX-107858159; COSMIC: COSV60372485;