rs879255591

Variant names:

• chrX-10185075-G-A
• rs879255591
• NM_001830.4:c.43G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3 PP5

The NM_001830.4(CLCN4):​c.43G>A​(p.Asp15Asn) 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D15V) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 23)
• Consequence: CLCN4 NM_001830.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.80
• Publications: 3 publications found

Genes affected

CLCN4 (HGNC:2022): (chloride voltage-gated channel 4) The CLCN family of voltage-dependent chloride channel genes comprises nine members (CLCN1-7, Ka and Kb) which demonstrate quite diverse functional characteristics while sharing significant sequence homology. Chloride channel 4 has an evolutionary conserved CpG island and is conserved in both mouse and hamster. This gene is mapped in close proximity to APXL (Apical protein Xenopus laevis-like) and OA1 (Ocular albinism type I), which are both located on the human X chromosome at band p22.3. The physiological role of chloride channel 4 remains unknown but may contribute to the pathogenesis of neuronal disorders. Alternate splicing results in two transcript variants that encode different proteins. [provided by RefSeq, Mar 2012]

CLCN4 Gene-Disease associations (from GenCC):

• non-syndromic X-linked intellectual disability

  Inheritance: XL Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• intellectual disability, X-linked 49

  Inheritance: XL Classification: STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.787
• PP5: Variant X-10185075-G-A is Pathogenic according to our data. Variant chrX-10185075-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 224910.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLCN4	NM_001830.4	c.43G>A	p.Asp15Asn	missense_variant	Exon 3 of 13	ENST00000380833.9	NP_001821.2
CLCN4	NM_001256944.2	c.-38-9836G>A		intron_variant	Intron 2 of 10		NP_001243873.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLCN4	ENST00000380833.9	c.43G>A	p.Asp15Asn	missense_variant	Exon 3 of 13	1	NM_001830.4	ENSP00000370213.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Mar 04, 2016

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The D15N variant in the CLCN4 gene has been previously reported in one individual with congenital diaphragmatic hernia (Yu et al., 2015). This variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The D15N variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. The D15N variant is asemi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. This substitution occurs at a position that is conserved across species. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. The D15N variant is a strong candidate for a pathogenic variant. -

CLCN4-related disorder Uncertain:1

Mar 22, 2016

Sydney Children's Hospital, SCHN

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

De novo variant. Additional non-neurological features not seen in other patients with CLCN4 related disorder. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.35
BayesDel_addAF	Uncertain	0.037	T
BayesDel_noAF	Benign	-0.18
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.21	T;T;.
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;D
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	0.79	D;D;D
MetaSVM	Uncertain	0.64	D
MutationAssessor	Benign	1.9	L;.;.
PhyloP100		9.8
PrimateAI	Pathogenic	0.82	D
PROVEAN	Benign	-1.7	N;N;N
REVEL	Uncertain	0.54
Sift	Uncertain	0.0060	D;D;D
Sift4G	Benign	0.14	T;T;D
Polyphen		0.65	P;.;.
Vest4		0.73
MutPred		0.46		Gain of relative solvent accessibility (P = 0.0479);Gain of relative solvent accessibility (P = 0.0479);Gain of relative solvent accessibility (P = 0.0479);
MVP		0.99
MPC		1.6
ClinPred		0.92	D
GERP RS		5.0
Varity_R		0.53
gMVP		0.95
Mutation Taster		=18/82	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: rs879255591; hg19: chrX-10153115; COSMIC: COSV108237624;