X-108626218-G-T

Variant names:

• chrX-108626218-G-T
• rs104886214
• NM_033380.3:c.3115G>T

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.3115G>T​(p.Gly1039Cys) 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1039D) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: COL4A5 NM_033380.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.94
• Publications: 0 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 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 1 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-108626219-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 547093.
• 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, 0.993
• PP5: Variant X-108626218-G-T is Pathogenic according to our data. Variant chrX-108626218-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2636792.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.3115G>T	p.Gly1039Cys	missense_variant	Exon 36 of 53	ENST00000328300.11	NP_203699.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL4A5	ENST00000328300.11	c.3115G>T	p.Gly1039Cys	missense_variant	Exon 36 of 53	1	NM_033380.3	ENSP00000331902.7
COL4A5	ENST00000483338.1	c.1939G>T	p.Gly647Cys	missense_variant	Exon 20 of 20	1		ENSP00000495685.1
COL4A5	ENST00000361603.7	c.3115G>T	p.Gly1039Cys	missense_variant	Exon 36 of 51	2		ENSP00000354505.2
COL4A5	ENST00000505728.1	c.346G>T	p.Gly116Cys	missense_variant	Exon 4 of 5	3		ENSP00000424137.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 22

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

COL4A5-related disorder Pathogenic:1

Oct 11, 2022

PreventionGenetics, part of Exact Sciences

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The COL4A5 c.3115G>T variant is predicted to result in the amino acid substitution p.Gly1039Cys. The p.Gly1039 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/).To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. At PreventionGenetics, we have observed this variant in two family members with features of COL4A5-related disorders (internal data). A different amino acid change at this position (p.Gly1039Ser) was previously reported in an individual with Alport syndrome (Knebelmann et al. 1996. PubMed ID: 8940267). This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.89
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	.;D;D
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D;D;T
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	0.86	D
MutationAssessor	Pathogenic	4.4	H;H;.
PhyloP100		8.9
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-7.2	D;D;.
REVEL	Pathogenic	0.98
Sift	Uncertain	0.0010	D;D;.
Sift4G	Pathogenic	0.0	D;D;.
Polyphen		1.0	.;D;D
Vest4		0.98
MutPred		0.99		Loss of catalytic residue at P1035 (P = 0.0672);Loss of catalytic residue at P1035 (P = 0.0672);.;
MVP		1.0
MPC		0.32
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		1.0
Mutation Taster		=2/98	disease causing

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: rs104886214; hg19: chrX-107869448; COSMIC: COSV100090512;