rs281874681

Positions:

• chrX-108598778-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP5_Moderate

The NM_033380.3(COL4A5):​c.1856C>T​(p.Pro619Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P619S) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 23)
• Consequence: COL4A5 NM_033380.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 2.39

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a compositionally_biased_region Pro residues (size 22) in uniprot entity CO4A5_HUMAN there are 4 pathogenic changes around while only 1 benign (80%) in NM_033380.3
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-108598778-C-T is Pathogenic according to our data. Variant chrX-108598778-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2138696.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chrX-108598778-C-T is described in Lovd as [Likely_pathogenic]. Variant chrX-108598778-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL4A5	NM_033380.3	c.1856C>T	p.Pro619Leu	missense_variant	25/53	ENST00000328300.11	NP_203699.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL4A5	ENST00000328300.11	c.1856C>T	p.Pro619Leu	missense_variant	25/53	1	NM_033380.3	ENSP00000331902.7
COL4A5	ENST00000483338.1	c.680C>T	p.Pro227Leu	missense_variant	9/20	1		ENSP00000495685.1
COL4A5	ENST00000361603.7	c.1856C>T	p.Pro619Leu	missense_variant	25/51	2		ENSP00000354505.2

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 14, 2023

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 619 of the COL4A5 protein (p.Pro619Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with Alport syndrome (PMID: 11462238, 17660027, 19728970). It has also been observed to segregate with disease in related individuals. 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 not expected to disrupt COL4A5 protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.070
BayesDel_addAF	Uncertain	0.073	D
BayesDel_noAF	Benign	-0.13
CADD	Uncertain	24
DANN	Benign	0.70
DEOGEN2	Uncertain	0.53	.;D;T
FATHMM_MKL	Benign	0.71	D
LIST_S2	Uncertain	0.91	D;D;D
M_CAP	Pathogenic	0.48	D
MetaRNN	Uncertain	0.49	T;T;T
MetaSVM	Benign	-0.45	T
MutationAssessor	Benign	1.5	L;L;.
PrimateAI	Benign	0.44	T
PROVEAN	Uncertain	-2.8	D;N;.
REVEL	Uncertain	0.35
Sift	Benign	0.10	T;T;.
Sift4G	Benign	1.0	T;T;.
Polyphen		0.0080, 0.0030	.;B;B
Vest4		0.38
MutPred		0.76		Loss of glycosylation at P623 (P = 0.2517);Loss of glycosylation at P623 (P = 0.2517);.;
MVP		0.83
MPC		0.31
ClinPred		0.15	T
GERP RS		4.1
Varity_R		0.098
gMVP		0.59

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.53		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.53		Position offset: 30

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs281874681; hg19: chrX-107842008;