rs779593707

Variant names:

• chr1-16049884-C-CAATA
• rs779593707
• NM_000085.5:c.937_940dupAATA

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000085.5(CLCNKB):​c.937_940dupAATA​(p.Arg314LysfsTer2) variant causes a frameshift, stop gained change. The variant allele was found at a frequency of 0.0000161 in 1,613,786 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: CLCNKB NM_000085.5 frameshift, stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 4.65
• Publications: 0 publications found

Genes affected

CLCNKB (HGNC:2027): (chloride voltage-gated channel Kb) The protein encoded by this gene is a member of the family of voltage-gated chloride channels. Chloride channels have several functions, including the regulation of cell volume, membrane potential stabilization, signal transduction and transepithelial transport. This gene is expressed predominantly in the kidney and may be important for renal salt reabsorption. Mutations in this gene are associated with autosomal recessive Bartter syndrome type 3 (BS3). Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2009]

CLCNKB Gene-Disease associations (from GenCC):

• Bartter disease type 3

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• Bartter disease type 4B

  Inheritance: AR Classification: STRONG Submitted by: G2P
• Bartter syndrome type 4

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Gitelman syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-16049884-C-CAATA is Pathogenic according to our data. Variant chr1-16049884-C-CAATA is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 523321.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLCNKB	NM_000085.5	c.937_940dupAATA	p.Arg314LysfsTer2	frameshift_variant, stop_gained	Exon 10 of 20	ENST00000375679.9	NP_000076.2
CLCNKB	NM_001165945.2	c.430_433dupAATA	p.Arg145LysfsTer2	frameshift_variant, stop_gained	Exon 3 of 13		NP_001159417.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLCNKB	ENST00000375679.9	c.937_940dupAATA	p.Arg314LysfsTer2	frameshift_variant, stop_gained	Exon 10 of 20	1	NM_000085.5	ENSP00000364831.5

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151998 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251300 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000171 AC: 25 AN: 1461788 Hom.: 0 Cov.: 38 AF XY: 0.0000261 AC XY: 19 AN XY: 727206

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.0000216 AC: 24 AN: 1111950

Other (OTH) AF: 0.00 AC: 0 AN: 60382

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151998 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74240

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41336

American (AMR) AF: 0.00 AC: 0 AN: 15270

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4816

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67984

Other (OTH) AF: 0.00 AC: 0 AN: 2086

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

EpiCase AF: 0.000109

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Bartter disease type 3 Pathogenic:2

Jun 12, 2019

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was classified as: Likely pathogenic. The following ACMG criteria were applied in classifying this variant: PVS1,PM2. -

Jul 05, 2023

Intergen, Intergen Genetics and Rare Diseases Diagnosis Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Rare null variant, reported as pathogenic on Clinvar and LOVD databases. -

not provided Pathogenic:1

Jan 18, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg314Lysfs*2) in the CLCNKB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CLCNKB are known to be pathogenic (PMID: 24830959, 26920127, 28381550, 29254190). This variant is present in population databases (rs779593707, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with CLCNKB-related conditions. ClinVar contains an entry for this variant (Variation ID: 523321). For these reasons, this variant has been classified as Pathogenic. -

Hematuria;C0033687:Proteinuria Pathogenic:1

Jan 01, 2017

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		4.6
Mutation Taster		=15/185	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs779593707; hg19: chr1-16376379;