Why this review matters
Bardet-Biedl syndrome (BBS) is an inherited condition that can affect many parts of the body, including vision, appetite and weight regulation, development, metabolism, and the liver. For patients and families, this combination can mean navigating care from childhood onward while managing symptoms that do not always appear at the same time or with the same severity in every person.
A 2026 review in Die Ophthalmologie highlights the importance of recognizing BBS as both a retinal disease and a multisystem condition. It also points to two important developments: an approved treatment for obesity related to hyperphagia, or persistent increased hunger, and enrollment in an ocular gene therapy study for people with BBS1-associated retinal dystrophy.
A genetically and clinically diverse condition
BBS is caused by disease-causing variants in at least 26 genes. This genetic diversity helps explain why BBS can look different from one person to another. Even among people with the same diagnosis, the type and extent of eye disease and non-eye features can vary.
Characteristic features described in the review include congenital postaxial polydactyly—extra fingers or toes on the outer, little-finger or little-toe side—obesity, hyperphagia, and retinal dystrophy beginning in childhood. Retinal dystrophy refers to progressive dysfunction and degeneration of the retina, the light-sensitive tissue at the back of the eye. In BBS, this retinal involvement has a broad phenotypic spectrum, meaning that visual symptoms and retinal findings are not identical in every patient.
The condition may also involve developmental delay, diabetes mellitus, and fatty liver. These features underscore why BBS should not be managed as an eye condition alone. A person’s visual needs, nutritional and metabolic health, developmental support, and other medical concerns may all require attention over time.
Diagnosis should connect genetics, eyes, and whole-body health
The review emphasizes the molecular genetic heterogeneity of BBS. Genetic testing can identify the gene associated with an individual’s condition and can help clarify whether retinal disease is linked to a specific BBS gene, such as BBS1. This information is increasingly important as research studies begin to focus on defined genetic forms of retinal dystrophy.
At the same time, genetic information is only one part of care. Because BBS has variable extraocular manifestations, patients need assessment that considers the full syndrome rather than isolated symptoms. Identifying retinal dystrophy early in childhood and monitoring visual changes are important, but so are recognizing hyperphagia, obesity, diabetes, fatty liver, and developmental needs.
The authors recommend interdisciplinary care at specialized centers in addition to primary care. In practical terms, this approach brings together the expertise needed for a complex diagnosis: eye care alongside management of metabolic and other systemic features. Coordinated care can also help families avoid fragmented appointments and ensure that changes in one aspect of health are considered in the context of the whole condition.
What treatment looks like now
The review makes a clear distinction between available treatment for one major feature of BBS and the current lack of a specific treatment for the retinal dystrophy itself.
An approved therapy is available for hyperphagia-related obesity in BBS. This is significant because increased hunger and obesity can have substantial effects on daily life and long-term health. The availability of a targeted option for this aspect of BBS reflects growing recognition that treatment must address the underlying biology of symptoms, not solely their consequences.
For the retinal dystrophy, however, the review states that there is currently no specific therapeutic option. Eye care therefore remains centered on identifying and monitoring retinal disease and addressing patients’ evolving visual needs within comprehensive BBS care.
A gene therapy study for BBS1-associated retinal dystrophy
The research landscape is beginning to change. Since 2026, patients with BBS1-associated retinal dystrophy have been enrolled in an ocular gene therapy study of AXV-101. The study is evaluating preliminary safety and tolerability—essential early questions for any new therapy delivered to the eye.
This is an important milestone for the BBS community. It represents movement from understanding the genetic causes of BBS toward testing a gene-specific approach for retinal disease. However, the study is limited to retinal dystrophy associated with BBS1, and its current focus is safety and tolerability rather than demonstrating clinical benefit. Its results will be important for determining the next steps in development.
Looking ahead
The 2026 review presents BBS care as a field with two connected priorities: delivering coordinated, lifelong support for a multisystem disorder and advancing treatments tailored to specific genetic forms of disease. The approved option for hyperphagia-related obesity shows that targeted treatment can make a meaningful difference in BBS management. The AXV-101 study signals a new phase of investigation for BBS1-related retinal dystrophy.
As genetic knowledge expands and clinical research progresses, specialized interdisciplinary care will remain central. For patients and families, the future of BBS research is increasingly shaped by a combination of earlier recognition, gene-informed care, and trials designed to address the features of the condition that currently have no specific treatment.