Bardet-Biedl syndrome 6

Bardet-Biedl syndrome 6 is a multisystem condition that affects several body systems including the eyes, limbs, metabolic regulation, and cognitive development. It is caused by pathogenic variants in the MKKS gene, which plays a role in cellular processes that are critical for normal development. The condition is inherited in an autosomal recessive manner, meaning that affected individuals have inherited two copies of the abnormal gene, one from each parent. Although precise prevalence estimates are not well established, the manifestations usually become apparent in childhood, and the clinical features can vary in severity.

Individuals with Bardet-Biedl syndrome 6 typically present with a constellation of features affecting multiple organ systems. Characteristic findings include pigmentary retinopathy and postaxial polydactyly, which are reported in all affected individuals, as well as obesity that is consistently observed. Many individuals also experience cognitive challenges, often presenting as intellectual disability, highlighting the central nervous system involvement. Other features that may be seen in a subset of patients include diabetes mellitus, hypospadias in males or vaginal atresia in females, and renal cysts. Not all individuals experience all features, and severity varies considerably.

Bardet-Biedl syndrome 6 is caused by pathogenic variants in the MKKS gene. The MKKS gene encodes a protein that is important for the proper functioning and development of multiple tissues. The condition is inherited in an autosomal recessive pattern, meaning that an individual must receive one altered copy of the gene from each parent to manifest the disorder. This mode of inheritance implies that siblings of an affected individual have a 25% chance of inheriting the condition, and genetic counseling is often recommended for affected families to understand the risks and implications for family planning.

Currently, management of Bardet-Biedl syndrome 6 focuses on supportive care and symptom management, tailored to the individual’s specific needs. Since there are no treatments that are approved specifically for this condition, a multidisciplinary team is essential in addressing its diverse manifestations. Regular surveillance is an essential part of long-term care, with monitoring of vision, metabolic status, renal function, and cognitive development to detect complications early. Patients and families are encouraged to discuss treatment options and monitoring strategies with their healthcare team, and genetic counseling is an important component of care to help understand the condition and guide family planning.

The clinical course of Bardet-Biedl syndrome 6 is highly variable, with outcomes depending on the severity of symptoms, the age at which the condition is diagnosed, and access to specialized care. With current standards of care, many individuals are able to manage their symptoms into adulthood, although the progression of complications in different organ systems may vary among patients. Outcomes described in medical literature continue to evolve as standards of care improve, and regular monitoring plays an important role in managing potential complications over time. Families often find it helpful to connect with specialists familiar with this condition, and genetic counseling can provide guidance regarding future family planning.