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BBS1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

BBS1 gene

The BBS1 gene provides instructions for creating a protein essential for the formation and function of cilia, which are critical for sensory perception and chemical signaling.

Normal Function

The BBS1 gene provides instructions for making a protein found in cells throughout the body. The BBS1 protein is part of a complex of proteins that plays a critical role in the formation of cell structures called cilia. Cilia are microscopic, finger-like projections that extend from the surface of many types of cells. They are involved in cell movement and various chemical signaling pathways. Additionally, cilia are necessary for the perception of sensory input, such as sight, hearing, and smell.

Health Conditions Related to Genetic Changes

Bardet-Biedl syndrome

More than 30 mutations in the BBS1 gene have been identified in people with Bardet-Biedl syndrome. Mutations in this gene are the most common cause of the disorder, accounting for approximately one-quarter of all cases.

Most BBS1 gene mutations alter single protein building blocks (amino acids) or lead to the production of an abnormally short version of the protein. The most common mutation replaces the amino acid methionine with arginine at protein position 390 (Met390Arg or M390R).

Mutations in the BBS1 gene likely affect the normal formation and function of cilia. Defects in these structures disrupt important chemical signaling pathways during development, leading to abnormalities in sensory perception. Researchers believe that defective cilia are responsible for most features of Bardet-Biedl syndrome, including:

  • Vision loss
  • Obesity
  • Polydactyly (extra fingers and/or toes)
  • Kidney abnormalities
  • Intellectual disability

Genomic Location

The BBS1 gene is found on chromosome 11.

Frequently Asked Questions

Diagnosis combines clinical criteria (≥4 primary features such as retinal dystrophy, obesity, polydactyly, renal anomalies, learning difficulties) with molecular testing. A targeted BBS1 gene panel or whole‑exome sequencing is performed on blood DNA; if a pathogenic BBS1 variant is found, it confirms the genetic basis. In ambiguous cases, functional studies (e.g., ciliary protein localization in fibroblasts) may be used, but they are rarely needed in routine practice.
Renal involvement occurs in up to 30 % of BBS1 cases. Baseline renal ultrasound or MRI is recommended at diagnosis, followed by repeat imaging every 1‑2 years. Serum creatinine, eGFR, and urine protein/creatinine ratio should be checked annually. If abnormalities appear, refer to a nephrologist for possible ACE‑inhibitor therapy and dietary counseling to preserve kidney function.
There is no cure, but several interventions can slow deterioration: regular ophthalmology visits with optical coherence tomography to monitor retinal thickness; low‑vision aids (magnifiers, high‑contrast glasses); vitamin A supplementation only under specialist supervision (some studies suggest benefit in retinitis pigmentosa); and enrollment in clinical trials for gene‑therapy or neuroprotective agents targeting ciliary dysfunction. Early visual rehabilitation and orientation‑mobility training are essential for quality of life.
Standard lifestyle interventions (calorie‑controlled diet, regular exercise) are still first‑line, but patients often have a hypothalamic appetite dysregulation linked to ciliary defects. Adding a multidisciplinary team—dietitian experienced with genetic obesity, behavioral therapist, and possibly pharmacologic agents such as GLP‑1 agonists—can improve outcomes. Monitoring for metabolic syndrome and early treatment of insulin resistance are also important.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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