BSND

Chr 1AR

barttin CLCNK type accessory subunit beta

Also known as: BART, DFNB73

NCBI Gene: 7809ENSG00000162399UniProt: Q8WZ55

This gene encodes an essential beta subunit for CLC chloride channels. These heteromeric channels localize to basolateral membranes of renal tubules and of potassium-secreting epithelia of the inner ear. Mutations in this gene have been associated with Bartter syndrome with sensorineural deafness. [provided by RefSeq, Jul 2008]

Primary Disease Associations & Inheritance

Bartter syndrome, type 4aMIM #602522
AR
Sensorineural deafness with mild renal dysfunctionMIM #602522
AR
UniProtBartter syndrome 4A, neonatal, with sensorineural deafness
425
ClinVar variants
50
Pathogenic / LP
0.00
pLI score
0
Active trials
Clinical Summary— BSND
🧬
Gene-Disease Validity (ClinGen)
Bartter disease type 4A · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

⚡
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
50 Pathogenic / Likely Pathogenic· 130 VUS of 425 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Tolerant — LoF & missense variants common in population
LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.
1.78LOEUF
pLI 0.000
Z-score -0.60
OE 1.19 (0.78–1.78)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.
0.07Z-score
OE missense 0.99 (0.88–1.11)
190 obs / 192.6 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.
LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.1.19 (0.78–1.78)
0≤0.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.99 (0.88–1.11)
0≤0.61.4
Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.20
0≤1.21.6
LoF obs/exp: 14 / 11.8Missense obs/exp: 190 / 192.6Syn Z: -1.42

ClinVar Variant Classifications

425 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic32
Likely Pathogenic18
VUS130
Likely Benign196
Benign24
Conflicting25
32
Pathogenic
18
Likely Pathogenic
130
VUS
196
Likely Benign
24
Benign
25
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
8
4
20
0
32
Likely Pathogenic
7
5
6
0
18
VUS
3
107
17
3
130
Likely Benign
1
4
47
144
196
Benign
0
0
22
2
24
Conflicting
—25
Total19120112149425

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

BSND · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Gene2Phenotype Curations

BSND-related Bartter syndrome, type 4a

definitive
ARLoss Of FunctionAbsent Gene Product
Dev. DisordersEar
G2P ↗

Gene2Phenotype curations · DECIPHER consortium patient cohort (public variants) · deciphergenomics.org

OMIM — Genotype-Phenotype Relationships

1 OMIM entry

OMIM

Bartter syndrome, type 4a

MIM #602522

Molecular basis of disorder known

Autosomal recessive

Sensorineural deafness with mild renal dysfunction

MIM #602522

Molecular basis of disorder known

Autosomal recessive
📖
GeneReview available — BSND
Authoritative clinical overview · NCBI Bookshelf · Recommended first read
Open GeneReview ↗
Clinical Literature
Landmark / reviewRecent case evidence
Key Publications
Landmark & review papers · by relevance
PubMed
Mutation of BSND causes Bartter syndrome with sensorineural deafness and kidney failure.
Birkenhäger R et al.·Nat Genet
2001
Molecular biology of hereditary diabetes insipidus.
Fujiwara TM et al.·J Am Soc Nephrol
2005Review
Functional BSND variants in essential hypertension.
Sile S et al.·Am J Hypertens
2007Functional
Digenic mutations involving both the BSND and GJB2 genes detected in Bartter syndrome type IV.
Wang HH et al.·Int J Pediatr Otorhinolaryngol
2017Case report
Genetic causes of hypomagnesemia, a clinical overview.
Viering DHHM et al.·Pediatr Nephrol
2017Review
Clinical Findings and Genetic Analysis of Nine Mexican Families with Bartter Syndrome.
Hernández NEG et al.·Arch Med Res
2023
Identification of missense mutation (I12T) in the BSND gene and bioinformatics analysis.
Iqbal H et al.·J Biomed Biotechnol
2011
Clinical Features and Unusual Heterozygous Mutations in Patients with Renal Hypokalemia.
Zhang Y et al.·Clin Lab
2024Cohort
Phenotypic and genotypic characteristics of children with Bartter syndrome.
Güven S et al.·Turk J Pediatr
2022
Severe manifestation of Bartter syndrome Type IV caused by a novel insertion mutation in the BSND gene.
de Pablos AL et al.·Clin Nephrol
2014Case report
Top 10 resultsSearch PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
BSND: An emerging immunohistochemical marker that reliably distinguishes benign from malignant oncocytic salivary gland tumors.
Tandon A et al.·Hum Pathol
2025
The Utility of BSND Immunohistochemistry in the Differential Diagnosis of Oncocytic and Warthin-like Mucoepidermoid Carcinoma of Salivary Gland.
Xu B et al.·Head Neck Pathol
2024
An Unusual Case of BSND Gene-Related (Type IV) Bartter Syndrome Presenting as Antenatal Bartter Syndrome: A Case Report and Review of Literature.
Shajan AM et al.·Matern Fetal Med
2023🔓 Open AccessReview
Two novel homozygous missense mutations identified in the BSND gene in Moroccan patients with Bartter's syndrome.
Elrharchi S et al.·Int J Pediatr Otorhinolaryngol
2018Cohort
BSND is a Novel Immunohistochemical Marker for Oncocytic Salivary Gland Tumors.
Shinmura K et al.·Pathol Oncol Res
2018
Top 5 resultsSearch Europe PMC ↗

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →

External Resources

Links to major genomics databases and tools