rs104886298

Positions:

• chrX-108694908-A-G

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.4808A>G​(p.Tyr1603Cys) 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 (★★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: COL4A5 NM_033380.3 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.40

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]

COL4A5 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM1: In a domain Collagen IV NC1 (size 224) in uniprot entity CO4A5_HUMAN there are 8 pathogenic changes around while only 1 benign (89%) in NM_033380.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.98
• PP5: Variant X-108694908-A-G is Pathogenic according to our data. Variant chrX-108694908-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1803954.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-108694908-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL4A5	NM_033380.3	c.4808A>G	p.Tyr1603Cys	missense_variant	51/53	ENST00000328300.11	NP_203699.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL4A5	ENST00000328300.11	c.4808A>G	p.Tyr1603Cys	missense_variant	51/53	1	NM_033380.3	ENSP00000331902.7

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 22

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

X-linked Alport syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Oct 10, 2024	Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Likely Pathogenic. Following criteria are met: 0103 - Dominant negative and loss of function are known mechanisms of disease in this gene and are associated with X-linked Alport syndrome 1 (MIM#301050). Dominant negative is caused mostly glycine substitutions that affect the conformation of the protein, and loss of function can be caused by either protein truncating or missense variants (PMID: 24046192, PMID: 12028435). (I) 0110 - This gene is associated with X-linked dominant disease. Males are typically more severely affected than females (PMID: 19965530). (I) 0115 - Variants in this gene are known to have variable expressivity. There is intra-familial variability among affected carrier females, possibly due to variable X-inactivation (PMID: 14514738). (I) 0200 - Variant is predicted to result in a missense amino acid change from tyrosine to cysteine. (I) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (v2, v3, v4). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools and highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated C4 domain (DECIPHER). (SP) 0704 - Another missense variant comparable to the one identified in this case has limited previous evidence for pathogenicity. The variant p.(Tyr1603His) has been reported as pathogenic in the Global Variome shared LOVD. (SP) 0802 - This variant has moderate previous evidence of pathogenicity in unrelated individuals. The variant has previously been reported as pathogenic/likely pathogenic in individuals with X-linked Alport syndrome (ClinVar, Global Variome shared LOVD, PMID: 8887300, PMID: 12105244). (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) 1102 - Strong phenotype match for this individual. (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Likely pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics Munich, Klinikum Rechts Der Isar, TU München	Sep 07, 2021	- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 10, 2023

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. 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. ClinVar contains an entry for this variant (Variation ID: 1803954). This variant is also known as A4992>G. This missense change has been observed in individuals with clinical features of Alport syndrome (PMID: 12105244; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 1597 of the COL4A5 protein (p.Tyr1597Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.71	D
BayesDel_noAF	Pathogenic	0.78
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	.;D;.
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Pathogenic	0.92	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.7	.;H;.
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-8.5	D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.99
MutPred		0.84		.;Loss of sheet (P = 0.0817);.;
MVP		0.98
MPC		1.1
ClinPred		1.0	D
GERP RS		5.6
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: rs104886298; hg19: chrX-107938138; COSMIC: COSV60366412;