Bardet-Biedl syndrome 3

Bardet-Biedl syndrome 3 is a multisystem condition that affects several organ systems including the eyes, limbs, and neurological development. It is caused by pathogenic variants in the ARL6 gene, which plays a role in cellular processes that affect multiple tissues. Affected individuals typically present in childhood with a constellation of features such as postaxial polydactyly, visual impairments, and developmental delays. Precise prevalence estimates are not well established, and not all affected individuals exhibit all possible features, with symptoms varying significantly between individuals.

The clinical presentation of Bardet-Biedl syndrome 3 is characterized by a range of consistent and variable features. Nearly all affected individuals show postaxial polydactyly, visual impairment, pigmentary retinopathy, and nyctalopia, which are considered hallmark findings. In addition, global developmental delay is universally present, and many children also experience cognitive challenges, including intellectual disability. Other features such as obesity, renal hypoplasia, and tricuspid regurgitation occur in a subset of patients. Not all individuals experience all features, and severity varies considerably, reflecting the multisystem nature of the condition.

Bardet-Biedl syndrome 3 is caused by pathogenic variants in the ARL6 gene. The ARL6 gene is critical for normal cellular functions that impact multiple organ systems, and disruptions in this gene lead to the range of clinical manifestations seen in this condition. It is inherited in an autosomal recessive pattern, meaning that an individual must inherit two altered copies of the gene, one from each parent, to be affected. Families may benefit from genetic counseling as this inheritance pattern implies that siblings of an affected individual have a 25% chance of being affected if both parents are carriers.

Currently, management focuses on supportive care and symptom management since no FDA-approved treatments or foundational therapies are linked to Bardet-Biedl syndrome 3. Treatment is tailored to the individual and typically involves a multidisciplinary team that may include ophthalmologists, developmental specialists, and renal care providers. Regular surveillance is an essential part of long-term care, helping to detect complications early and allowing for timely intervention. Genetic counseling is also recommended to help families understand the condition and its inheritance, and patients should discuss treatment options with their healthcare team to determine the best approach for their individual needs.

The course of Bardet-Biedl syndrome 3 is highly variable, with outcomes depending on the severity of symptoms, age at diagnosis, and access to specialized care. With current standards of care, many individuals live into adulthood, and while some may experience progressive challenges, others may achieve a relatively stable condition over time. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists familiar with multisystem conditions and to seek genetic counseling for advice on management and family planning.

Clinical trials are underway exploring new treatment approaches for Bardet-Biedl syndrome 3. Although management is currently focused on supportive care, research into potential targeted therapies continues. Individuals interested in clinical trials can search ClinicalTrials.gov or consult their care team to learn about current studies and eligibility.