BSND

Chr 1AR

barttin CLCNK type accessory subunit beta

Also known as: BART, DFNB73

NCBI Gene: 7809 ENSG00000162399 OMIM: 606412

The protein encoded by this gene is an essential regulatory subunit for chloride channels in the kidney and inner ear, functioning as a chaperone that enables proper channel sorting and constitutive opening for basolateral chloride conductance. Mutations cause autosomal recessive Bartter syndrome type 4a with sensorineural deafness, affecting both renal salt wasting and hearing function. The gene shows very low constraint against loss-of-function variants (pLI ~0, LOEUF 1.78), consistent with recessive inheritance where heterozygous carriers are unaffected.

OMIM ResearchSummary from RefSeq, OMIM, UniProt

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]

OMIM ResearchGenerating clinical summary…

LOFmechanismARLOEUF 1.782 OMIM phenotypes

Clinical Summary— BSND

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Gene-Disease Validity (ClinGen)

Bartter disease type 4A · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

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Population Constraint (gnomAD)

Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

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?

0.07Z-score

OE missense 0.99 (0.88–1.11)

190 obs / 192.6 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?1.19 (0.78–1.78)

0≤0.351.4

Missense OE?0.99 (0.88–1.11)

0≤0.61.4

Synonymous OE?1.20

0≤1.21.6

LoF obs/exp: 14 / 11.8Missense obs/exp: 190 / 192.6Syn Z: -1.42

Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗

definitiveBSND-related Bartter syndrome, type 4aLOFAR

This gene — mechanism propensity

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

0.6551th %ile

GOF

0.73top 25%

LOF

0.3842th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.