Endocrine Abstracts

Introduction: Bardet-Biedl Syndrome (BBS) is an autosomal recessive disease and one of the most common causes of syndromic obesity. An excessive weight usually appears at an early age and affects almost 90% of patients. Mutations in BBS genes have been found to disrupt the function of the cilia, leading to disturbances of transduction satiety and hunger signals in hypothalamus and increased adipogenesis in the fat tissue.

Methods: We present a case series of eight pediatric patients (P1 to P8) with BBS (six boys and two girls) observed in one Medical Centre including two pairs of siblings.

Results: The age range at the moment of diagnosis was 1 month to 4 years (average 20 months). At presentation obesity was present only in four patients, whereas polydactyly and urinary system disorders was observed in six patients, psychomotor development delay in two patients. In two patients with kidney disorders and polydactyly, the genetic tests were ordered at the age of 2 and 6 months due to having ab older sibling with the diagnosis of BBS. Their weight-for-length z-scores at the age of one year were above 3.0 (P3=3.1, P5=3.7). The mutations in the following genes were confirmed: BBS10 (1), MKKS (P2, P3 – sibling, the same mutations), BBS7/BBS10 (P4, P5 - sibling, the same mutations), BBS7 (P6, P7, different mutations), BBS9 (P8). The duration of the follow up varied between 6 months to 9 years. All patients’ parents received diet training and lifestyle intervention at every office visit. During follow up seven out of eight patients developed obesity at some point. Only P7 had never developed excessive weight (the highest BMI z-score 0.55). In six patients an excessive increase of body weight was observed, only in one case BMI z-score decreased (P8) and in another one remained stable during observation (P7). In P1 the obesity class 3 (BMI z-score 4.37) was diagnosed with multiple metabolic disorders (MAFLD, hypertension, insulin resistance, dyslipidemia). In the other one patient hypertriglyceridemia with increased LDL-cholesterol was found and in another three – isolated hypertriglyceridemia was present.

Conclusion: Obesity is one of the main therapeutic challenges while handling patients with BBS, even though it is not often the reason for starting diagnostics for this disease. It is necessary to bring awareness about this syndrome among pediatricians in order to allow for earlier diagnosis and ensure patients’ better prognosis.