chr1-16024773-G-T

Variant names:

• chr1-16024773-G-T
• rs121909137
• NM_004070.4:c.240G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PS1 PM2 PP3_Strong

The NM_004070.4(CLCNKA):​c.240G>T​(p.Trp80Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,200 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Pathogenic in ClinVar.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: CLCNKA NM_004070.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.01
• Publications: 5 publications found

Genes affected

CLCNKA (HGNC:2026): (chloride voltage-gated channel Ka) This gene is a member of the CLC family of voltage-gated chloride channels. The encoded protein is predicted to have 12 transmembrane domains, and requires a beta subunit called barttin to form a functional channel. It is thought to function in salt reabsorption in the kidney and potassium recycling in the inner ear. The gene is highly similar to CLCNKB, which is located 10 kb downstream from this gene. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

CLCNKA Gene-Disease associations (from GenCC):

• Bartter disease type 4B

  Inheritance: Unknown, AR Classification: MODERATE, LIMITED Submitted by: Ambry Genetics, G2P
• Bartter syndrome type 4

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PS1: Transcript NM_004070.4 (CLCNKA) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004070.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CLCNKA	NM_004070.4	MANE Select	c.240G>T	p.Trp80Cys	missense	Exon 4 of 20	NP_004061.3
	CLCNKA	NM_001042704.2		c.240G>T	p.Trp80Cys	missense	Exon 4 of 20	NP_001036169.1
	CLCNKA	NM_001257139.2		c.229+845G>T		intron	N/A	NP_001244068.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CLCNKA	ENST00000331433.5	TSL:1 MANE Select	c.240G>T	p.Trp80Cys	missense	Exon 4 of 20	ENSP00000332771.4
	CLCNKA	ENST00000375692.5	TSL:1	c.240G>T	p.Trp80Cys	missense	Exon 5 of 21	ENSP00000364844.1
	CLCNKA	ENST00000495784.1	TSL:5	n.398G>T		non_coding_transcript_exon	Exon 4 of 6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152200 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 Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152200 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74348

⚠️ 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: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2090

⚠️ 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.

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.73
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.68	D
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Pathogenic	3.5	H
PhyloP100		9.0
PrimateAI	Uncertain	0.62	T
PROVEAN	Pathogenic	-12	D
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.86
MutPred		0.89		Gain of catalytic residue at L81 (P = 0.0718)
MVP		0.98
MPC		1.4
ClinPred		1.0	D
GERP RS		4.0
Varity_R		0.90
gMVP		0.63
Mutation Taster		=6/94	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs121909137; hg19: chr1-16351268;