CLCNKB p.Ala77Glu

Variant names:

• chr1-16045687-G-A
• NM_000085.5:c.229+1G>A

Your query was ambiguous. Multiple possible variants found:

• chr1-16045687-C-A
• chr1-16045687-CG-AA

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_000085.5(CLCNKB):​c.229+1G>A variant causes a splice donor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CLCNKB NM_000085.5 splice_donor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.45
• 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: Labcorp Genetics (formerly Invitae), Orphanet
• 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: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.0625 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.9, offset of 18, new splice context is: cagGTgctg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000085.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CLCNKB	NM_000085.5	MANE Select	c.229+1G>A		splice_donor intron	N/A	NP_000076.2	P51801-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CLCNKB	ENST00000375679.9	TSL:1 MANE Select	c.229+1G>A		splice_donor intron	N/A	ENSP00000364831.5	P51801-1
	CLCNKB	ENST00000906265.1		c.230G>A	p.Gly77Asp	missense	Exon 3 of 20	ENSP00000576324.1
	CLCNKB	ENST00000906262.1		c.230G>A	p.Gly77Asp	missense	Exon 3 of 20	ENSP00000576321.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.5
Mutation Taster		=12/88	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.81		Position offset: 17
DS_DL_spliceai		0.99		Position offset: -1

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr1-16372182;