rs281874669

Positions:

• chrX-108559064-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3_Strong PP5_Moderate

The NM_033380.3(COL4A5):​c.142G>A​(p.Gly48Arg) variant causes a missense, splice region 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. 13/22 in silico tools predict a damaging outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: COL4A5 NM_033380.3 missense, splice_region
• Scores: Splicing: ADA: 0.9977
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.09

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant X-108559064-G-A is Pathogenic according to our data. Variant chrX-108559064-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3254648.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chrX-108559064-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL4A5	NM_033380.3	c.142G>A	p.Gly48Arg	missense_variant, splice_region_variant	3/53	ENST00000328300.11	NP_203699.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL4A5	ENST00000328300.11	c.142G>A	p.Gly48Arg	missense_variant, splice_region_variant	3/53	1	NM_033380.3	ENSP00000331902.7
COL4A5	ENST00000361603.7	c.142G>A	p.Gly48Arg	missense_variant, splice_region_variant	3/51	2		ENSP00000354505.2
COL4A5	ENST00000470339.1	n.326G>A		splice_region_variant, non_coding_transcript_exon_variant	3/6	3

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

X-linked Alport syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Jul 17, 2023

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Likely Pathogenic. The 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 by 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, 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 intrafamilial 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 glycine to arginine. (I) 0253 - This variant is hemizygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0601 - Variant is located in the well-established functional triple helical domain. Residue affected is the Gly of the G-X-Y repeat (DECIPHER). (SP) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0803 - This variant has limited previous evidence of pathogenicity in unrelated individuals. This variant has been reported in an X-linked Alport syndrome study, where no individual clinical details were provided (PMID: 19965530), and in an individual with Alport syndrome (VCGS). It has also been reported as pathogenic in LOVD and the ARUP Alport syndrome database (PMID: 19965530, PMID: 20574986). (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 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.74	.;D
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	H;H
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-7.1	D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.86
MutPred		0.96		Loss of methylation at R50 (P = 0.108);Loss of methylation at R50 (P = 0.108);
MVP		1.0
MPC		0.36
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.95
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
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: rs281874669; hg19: chrX-107802294;