B9D1

Chr 17AR

B9 domain containing 1

Also known as: B9, EPPB9, JBTS27, MKS9, MKSR-1, MKSR1

The protein is a component of the tectonic-like complex that localizes to the transition zone of primary cilia and functions as a barrier preventing diffusion of transmembrane proteins between cilia and plasma membranes, and is required for ciliogenesis and sonic hedgehog signaling. Mutations cause Meckel syndrome 9 and Joubert syndrome 27, both severe ciliopathies affecting multiple organ systems including the brain, kidneys, and liver. Inheritance is autosomal recessive.

GeneReviewsOMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismARLOEUF 0.952 OMIM phenotypes
Clinical SummaryB9D1
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Gene-Disease Validity (ClinGen)
ciliopathy · 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.
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GeneReview available — B9D1
Authoritative clinical overview · Recommended first read
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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.95LOEUF
pLI 0.003
Z-score 1.69
OE 0.48 (0.260.95)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.10Z-score
OE missense 0.97 (0.841.13)
121 obs / 124.2 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.48 (0.260.95)
00.351.4
Missense OE0.97 (0.841.13)
00.61.4
Synonymous OE1.11
01.21.6
LoF obs/exp: 6 / 12.4Missense obs/exp: 121 / 124.2Syn Z: -0.58

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

B9D1 · protein map & ClinVar variants

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

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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