1-16044527-CA-C

Variant names:

• chr1-16044527-CA-C
• rs1260198649
• NM_000085.5:c.36delA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000085.5(CLCNKB):​c.36delA​(p.Asn14ThrfsTer3) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000685 in 1,606,824 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000069 (0 hom.)
• Consequence: CLCNKB NM_000085.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: -7.85

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 61 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-16044527-CA-C is Pathogenic according to our data. Variant chr1-16044527-CA-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3340600.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.36delA	p.Asn14ThrfsTer3	frameshift_variant	Exon 2 of 20	ENST00000375679.9	NP_000076.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLCNKB	ENST00000375679.9	c.36delA	p.Asn14ThrfsTer3	frameshift_variant	Exon 2 of 20	1	NM_000085.5	ENSP00000364831.5

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152154 Hom.: 0 Cov.: 33

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

GnomAD4 exome AF: 0.00000687 AC: 10 AN: 1454670 Hom.: 0 Cov.: 31 AF XY: 0.00000830 AC XY: 6 AN XY: 722628

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: 0.00000901

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152154 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74318

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Apr 09, 2024

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.Asn14Thrfs*3) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with CLCNKB-related conditions (PMID: 28381550). For these reasons, this variant has been classified as Pathogenic. -

Mar 19, 2024

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in the published literature in a patient with Gitelman syndrome and in a patient with Bartter syndrome; both patients harbored additional variants; however, detailed clinical and segregation information was not provided (PMID: 28381550); Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 28381550) -

Bartter disease type 3;C4310805:Bartter disease type 4B Pathogenic:1

May 31, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

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

LitVar

Other links and lift over

dbSNP: rs1260198649; hg19: chr1-16371022;