X-108626300-G-T

Position:

• chrX-108626300-G-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_033380.3(COL4A5):​c.3197G>T​(p.Gly1066Val) 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1066R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: COL4A5 NM_033380.3 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.03

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.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant X-108626300-G-T is Pathogenic according to our data. Variant chrX-108626300-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 804587.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL4A5	NM_033380.3	c.3197G>T	p.Gly1066Val	missense_variant	36/53	ENST00000328300.11	NP_203699.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL4A5	ENST00000328300.11	c.3197G>T	p.Gly1066Val	missense_variant	36/53	1	NM_033380.3	ENSP00000331902.7
COL4A5	ENST00000483338.1	c.2021G>T	p.Gly674Val	missense_variant	20/20	1		ENSP00000495685.1
COL4A5	ENST00000361603.7	c.3197G>T	p.Gly1066Val	missense_variant	36/51	2		ENSP00000354505.2
COL4A5	ENST00000505728.1	c.428G>T	p.Gly143Val	missense_variant	4/5	3		ENSP00000424137.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 04, 2021	For these reasons, this variant has been classified as Pathogenic. 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.Gly1066 amino acid residue in COL4A5. Other variant(s) that disrupt this residue have been observed in individuals with COL4A5-related conditions (PMID: 11223851, 8940267, Invitae), which suggests that this may be a clinically significant amino acid residue. 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 has not been reported in the literature in individuals with COL4A5-related conditions. ClinVar contains an entry for this variant (Variation ID: 804587). This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with valine at codon 1066 of the COL4A5 protein (p.Gly1066Val). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and valine. -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Sep 14, 2018	The variant disrupts a glycine residue in the canonical Gly-X-Y repeats of the triple helix domain, which are required for stability and structure of this protein. Therefore it is expected to severely affect the function of the protein. Found in at least one symptomatic patient, and not found in general population data. -

COL4A5-related disorder Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 07, 2024

The COL4A5 c.3197G>T variant is predicted to result in the amino acid substitution p.Gly1066Val. To our knowledge, this variant has not been reported in the literature or in a large population database, indicating this variant is rare. The p.Gly1066 residue resides in the triple-helical region (residues 42 – 1456) of the COL4A5 protein (uniprot.org). The majority of pathogenic variants in COL4A5 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/). Alternate nucleotide changes affecting the same amino acid (p.Gly1066Ser, p.Gly1066Arg, p.Gly1066Ala) have been reported to be pathogenic for Alport syndrome (Martin et al. 1998. PubMed ID: 9848783; Knebelmann et al. 1996. PubMed ID: 8940267; Barker et al. 2001. PubMed ID: 11223851). This variant is interpreted as likely pathogenic. -

X-linked Alport syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Dec 21, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	.;D;D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Uncertain	0.76	D
MutationAssessor	Pathogenic	4.5	H;H;.
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-7.4	D;D;.
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D;.
Sift4G	Pathogenic	0.0	D;D;.
Polyphen		1.0	.;D;D
Vest4		0.98
MutPred		0.99		Loss of relative solvent accessibility (P = 0.0186);Loss of relative solvent accessibility (P = 0.0186);.;
MVP		1.0
MPC		0.37
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.99
gMVP		0.99

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: rs104886221; hg19: chrX-107869530;