The prevalence of obesity in children is still rising all over the world. The most common reason for significant weight gain is a high-calorie diet and decreased physical activity. However, apart from environmental factors, genetic predisposition plays a crucial role in the pathomechanism of obesity. We present the case of a boy with pathological obesity and Bardet-Biedl syndrome (BBS). BBS is a ciliopathy, a heterogeneous group of rare disorders associated with defects in primary cilia. Other clinical signs and symptoms of BBS are: polydactyly, hypertension, hyperlipidemia, hypogonadotrophic hypogonadism, intellectual disability, rod-cone dystrophy, genitourinary and renal abnormalities.
Conclusions: genetic factors of rapid weight gain should be taken into consideration in a child with obesity. Polydactyly can be associated with ciliopathy. A patient with Bardet-Biedl syndrome requires multi-specialist care.
Keywords: ciliopathy; dysplastic kidney; obesity; polydactyly; retinitis pigmentosa.