Home / Deep Research / Bardet-Biedl syndrome

Bardet-Biedl syndrome

Bardet-Biedl syndrome curation notes

2026-04-13
OpenAI MONDO:0015229 Model: gpt-5.4 17 citations

Bardet-Biedl syndrome curation notes

Disease framing

  • Curate this as classic syndromic Bardet-Biedl syndrome, not as a loose bucket for every "BBS-like" ciliopathy.
  • Keep the disease-level entry unified because the core mechanistic story is shared across established BBS genes: defective BBSome-dependent ciliary cargo trafficking.
  • Capture genotype-specific severity differences in genetic: notes rather than exploding the entry into dozens of gene-specific subtypes. The strongest repeatedly supported contrasts are BBS1 versus BBS10.
  • Useful framing papers for this boundary:
  • PMID:30614526 states BBS is a heterogeneous ciliopathy with "22 known genes" and retains the classic syndrome definition.
  • PMID:41219488 and PMID:37031301 show continued heterogeneity across recent molecular cohorts.

Core mechanistic backbone

  1. Biallelic pathogenic variants in established BBS genes initiate disease. Representative human cohort support: PMID:30614526, PMID:41219488.
  2. These defects impair BBSome assembly or its chaperonin-assisted maturation. Best mechanistic assembly papers: PMID:22500027 and PMID:20080638.
  3. An incompletely assembled BBSome disrupts ciliary cargo trafficking. Neuronal GPCR-trafficking support: PMID:36699005.
  4. Tissue-specific consequences then branch:
  5. Hypothalamus: impaired LepR trafficking/signaling drives leptin resistance, hyperphagia, and obesity (PMID:19150989, PMID:21209035, PMID:23776152, PMID:32700463).
  6. Retina: rhodopsin mislocalization and photoreceptor death drive the invariant retinal dystrophy phenotype and progressive visual loss (PMID:15539463, PMID:35886001, PMID:22358239, PMID:41219488).
  7. Kidney: renal dysmorphism, impaired function, and chronic tubulointerstitial disease are frequent and prognostically important (PMID:20876674, PMID:41219488).
  8. Limb bud: altered Sonic hedgehog-dependent patterning explains postaxial polydactyly (PMID:18381349).

Human phenotype and genotype highlights

  • Retinal dystrophy is the most stable phenotype anchor.
  • PMID:35886001: all patients in the German ophthalmic cohort had retinal dystrophy.
  • PMID:41219488: retinal dystrophy 94.1%.
  • Polydactyly and obesity are frequent but less invariant than retinal disease.
  • PMID:41219488: polydactyly 88.0%, obesity 68.0%.
  • PMID:32700463: overweight/obesity exceeded 90% after age 5 in the large pediatric registry.
  • Kidney disease is common but more variable across cohorts.
  • PMID:20876674: renal abnormalities in 82%.
  • PMID:41219488: renal anomalies in 52.0%.
  • PMID:37031301: renal anomalies only 7.1% in that Chinese cohort, which is a reminder not to overstate invariance.
  • BBS1 and BBS10 are the most reproducibly common genotype groups in many cohorts.
  • PMID:35886001: BBS10 32.8%, BBS1 24.6%.
  • PMID:21209035: BBS10 30%, BBS1 27%.
  • PMID:28143435: BBS1 followed by BBS10.
  • BBS10 is the clearest severity signal.
  • PMID:28143435 links BBS10 to worse renal and ocular outcomes.
  • PMID:20876674 links BBS6/BBS10/BBS12 genotypes to more severe renal disease.

Treatment curation choices

  • Include setmelanotide because it has direct BBS phase 3 human evidence and a clear mechanistic rationale as downstream MC4R agonism (PMID:36356613).
  • Include kidney transplantation because registry data support it for the ESRD subset (PMID:27245600).
  • Do not overspecify generic supportive care unless the claim is directly abstract-supported for BBS itself.

Evidence-quality decisions

  • Prefer exact PMID-backed quotations from cohort abstracts or mechanistic abstracts over generic review prose.
  • Use HUMAN_CLINICAL for patient cohorts, registries, transplant series, and trials.
  • Use MODEL_ORGANISM for mouse or zebrafish mechanism papers.
  • Use OTHER only where the abstract itself mixes multiple experimental modes and cannot be cleanly split without misclassifying the publication-level evidence.

Claims intentionally downweighted or excluded

  • Broad "all BBS genes" lists beyond clearly established syndrome genes were not overexpanded into the YAML because the disease entry should stay syndrome-level and mechanistically coherent.
  • Behavioral, craniofacial, cardiac, and hearing findings were not made central pathophysiology nodes because the strongest disease-level mechanistic evidence is still the retina-hypothalamus-kidney-limb axis.
  • Histopathology was not added as a standalone section even though PMID:20876674 supports chronic interstitial nephropathy of dysplastic nature; the evidence is used directly in the renal pathophysiology and phenotype instead.