rs104886139

Variant names:

• chrX-108597524-G-A
• rs104886139
• NM_033380.3:c.1735G>A

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Moderate

The NM_033380.3(COL4A5):​c.1735G>A​(p.Gly579Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000911 in 1,097,589 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. 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. G579E) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 21)
  • Exomes 𝑓: 9.1e-7 (0 hom. 0 hem.)
• Consequence: COL4A5 NM_033380.3 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.95
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• Alport syndrome

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen, G2P
• X-linked Alport syndrome

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Genomics England PanelApp, Myriad Women’s Health, Orphanet, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 13 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_033380.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrX-108597525-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2439396.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 538 curated pathogenic missense variants (we use a threshold of 10). The gene has 138 curated benign missense variants. Gene score misZ: 2.4995 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to X-linked Alport syndrome, Alport syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant X-108597524-G-A is Pathogenic according to our data. Variant chrX-108597524-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 1391700.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL4A5	NM_033380.3	c.1735G>A	p.Gly579Arg	missense_variant	Exon 24 of 53	ENST00000328300.11	NP_203699.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL4A5	ENST00000328300.11	c.1735G>A	p.Gly579Arg	missense_variant	Exon 24 of 53	1	NM_033380.3	ENSP00000331902.7
COL4A5	ENST00000483338.1	c.559G>A	p.Gly187Arg	missense_variant	Exon 8 of 20	1		ENSP00000495685.1
COL4A5	ENST00000361603.7	c.1735G>A	p.Gly579Arg	missense_variant	Exon 24 of 51	2		ENSP00000354505.2

Frequencies

GnomAD3 genomes Cov.: 21

GnomAD4 exome AF: 9.11e-7 AC: 1 AN: 1097589 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 363087

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 26386

American (AMR) AF: 0.00 AC: 0 AN: 35199

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19381

East Asian (EAS) AF: 0.00 AC: 0 AN: 30193

South Asian (SAS) AF: 0.00 AC: 0 AN: 54102

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40514

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3826

European-Non Finnish (NFE) AF: 0.00000119 AC: 1 AN: 841937

Other (OTH) AF: 0.00 AC: 0 AN: 46051

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 21

Alfa AF: 0.0000657 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Apr 23, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 sequence change replaces glycine with arginine at codon 579 of the COL4A5 protein (p.Gly579Arg). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and arginine. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with clinical features of Alport syndrome (PMID: 10094548, Invitae). ClinVar contains an entry for this variant (Variation ID: 24440). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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). For these reasons, this variant has been classified as Pathogenic. -

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	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.73	.;D;T
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	4.1	H;H;.
PhyloP100		9.9
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-7.7	D;D;.
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;D;.
Sift4G	Pathogenic	0.0	D;D;.
Polyphen		1.0	.;D;D
Vest4		0.99
MutPred		0.98		Gain of methylation at G579 (P = 0.0373);Gain of methylation at G579 (P = 0.0373);.;
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		0.94
gMVP		1.0
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs104886139; hg19: chrX-107840754;