chrX-108601867-A-G

Position:

• chrX-108601867-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3 PP5_Moderate

The NM_033380.3(COL4A5):​c.2042-18A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). There are indicators that this mutation may affect the branch point..

• Frequency:
  • Genomes: not found (cov: 22)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: COL4A5 NM_033380.3 intron
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.49

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 Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant X-108601867-A-G is Pathogenic according to our data. Variant chrX-108601867-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 3255205.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chrX-108601867-A-G is described in Lovd as [Pathogenic]. Variant chrX-108601867-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A5	NM_033380.3	c.2042-18A>G		intron_variant		ENST00000328300.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A5	ENST00000328300.11	c.2042-18A>G		intron_variant		1	NM_033380.3
COL4A5	ENST00000483338.1	c.866-18A>G		intron_variant		1
COL4A5	ENST00000361603.7	c.2042-18A>G		intron_variant		2		P1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 864454 Hom.: 0 Cov.: 14 AF XY: 0.00 AC XY: 0 AN XY: 243742

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

X-linked Alport syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Dec 21, 2023

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as 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 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) 0210 - Splice site variant proven to affect splicing of the transcript with a known effect on protein sequence. RNA studies performed on a patient sample revealed exon 27 skipping (PMID: 31481700). (SP) 0253 - This variant is hemizygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0601 - Variant is located in the well-established functional domain. This variant results in exon 27 skipping which encodes a Gly-X-Y region in the collagen triple helical domain (DECIPHER). (SP) 0803 - This variant has limited previous evidence of pathogenicity in unrelated individuals. This variant has been reported in two individuals with Alport syndrome (PMIDs: 19965530, 25183659). (SP) 0906 - Segregation evidence for this variant is inconclusive. This variant has been identified in an individual with Alport syndrome and their brother whom has end-stage renal failure, no further information is available for this family (PMID: 25183659). (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
BayesDel_noAF	Benign	-0.75
CADD	Benign	23
DANN	Benign	0.79
BranchPoint Hunter		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.58		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.58		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: rs104886341; hg19: chrX-107845097;