rs104886337

chrX-108597569-G-AchrX-108597569-G-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Very_Strong

The NM_033380.3(COL4A5):c.1779+1G>A variant causes a splice donor 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: COL4A5 NM_033380.3 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.95

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 Pathogenic. Variant got 16 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.037628055 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant X-108597569-G-A is Pathogenic according to our data. Variant chrX-108597569-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 585538.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-108597569-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A5	NM_033380.3	c.1779+1G>A		splice_donor_variant		ENST00000328300.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A5	ENST00000328300.11	c.1779+1G>A		splice_donor_variant		1	NM_033380.3
COL4A5	ENST00000483338.1	c.603+1G>A		splice_donor_variant		1
COL4A5	ENST00000361603.7	c.1779+1G>A		splice_donor_variant		2		P1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 22

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Feb 04, 2020	Canonical splice site variant predicted to result in in-frame deletion within a critical region. Variant damages or destroys the canonical splice donor site in intron 24, and is expected to cause abnormal gene splicing; if the splice outcome is exon skip, the loss of the encoded residues in the triple helical region is expected to disrupt normal protein folding and function; Not observed in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 22921432) -
Likely pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Sep 11, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Mar 23, 2022	For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 585538). Disruption of this splice site has been observed in individuals with Alport syndrome (PMID: 8651296, 22921432). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 24 of the COL4A5 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in COL4A5 are known to be pathogenic (PMID: 9195222, 10752524, 14514738, 24854265, 26809805). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.39
Cadd	Pathogenic	35
Dann	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.96
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.75		Position offset: 3
DS_DL_spliceai		0.98		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs104886337; hg19: chrX-107840799;