X-108159506-G-A

Position:

• chrX-108159506-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_033641.4(COL4A6):​c.4768C>T​(p.Pro1590Ser) 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 24)
• Consequence: COL4A6 NM_033641.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 10.0

Genes affected

COL4A6 (HGNC:2208): (collagen type IV alpha 6 chain) This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. 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, alpha 5 type IV collagen, so that the gene pair shares a common promoter. Deletions in the alpha 5 gene that extend into the alpha 6 gene result in diffuse leiomyomatosis accompanying the X-linked Alport syndrome caused by the deletion in the alpha 5 gene. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Dec 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.939

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A6	NM_033641.4	c.4768C>T	p.Pro1590Ser	missense_variant	44/45	ENST00000334504.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A6	ENST00000334504.12	c.4768C>T	p.Pro1590Ser	missense_variant	44/45	5	NM_033641.4	P4

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 24

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hearing loss, X-linked 6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Jun 24, 2022

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0105 - The mechanism of disease for this gene is not clearly established. However loss of function has been demonstrated for a splice variant found in a heterozygous female with a hearing impairment (PMID: 33840813). (I) 0109 - This gene is associated with X-linked disease. Hemizygous males have early onset severe hearing loss while heterozygous females can either be unaffected or mildly affected with later onset of symptoms (PMID: 23714752). (I) 0200 - Variant is predicted to result in a missense amino acid change from proline to serine. (I) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v3) (1 heterozygotes, 0 homozygotes). (I) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated C-terminal tandem repeated domain (DECIPHER). (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0807 - This variant has no previous evidence of pathogenicity. (I) 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	0.75
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	26
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-7.9	D;D;.;D;.;.
REVEL	Pathogenic	0.84
Sift	Pathogenic	0.0	D;D;.;D;.;.
Sift4G	Pathogenic	0.0	D;D;D;D;D;D
Polyphen		1.0	D;D;.;D;.;.
Vest4		0.65
MutPred		0.87		.;Gain of MoRF binding (P = 0.0981);.;.;.;.;
MVP		0.95
MPC		0.18
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.85
gMVP		0.92

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chrX-107402736;