Introduction: Bardet-Biedl Syndrome is a rare autosomal recessive disorder characterized by multisystem manifestations, such as early-onset obesity, hypogonadotropic hypogonadism, retinal dystrophy, polydactyly, renal anomalies and intellectual disability. Phenotypic variability makes diagnosis challenging. Central obesity and hypogonadotropic hypogonadism are frequently observed, but often overlooked. Case: We report a 12-year-old male who was referred at the age of 10 years for evaluation of central obesity and buried penis. He was born at term with birth weight of 3,200 g. Both parents were non-consanguineous, and antenatal history was unremarkable. Early-onset excessive weight gain was noted from infancy, with hyperphagia during early childhood. His weight remained persistently above the 95th centile, and height around the 90th centile, slightly exceeding midparental height expectations. Buried penis was identified at birth. Polydactyly is absent. He also demonstrates learning difficulties. Early diagnostic considerations include Klinefelter syndrome due to buried penis, and PraderWilli Syndrome due to central obesity with co-existence of learning difficulties. Further evaluation excluded PraderWilli Syndrome, and conventional karyotyping ruled out Klinefelter syndrome. Clinical assessment revealed prepubertal Tanner stage, bilaterally palpable testes (3 mL), and a stretched penile length <2 cm. Endocrine evaluation demonstrated a prepubertal response to LHRH stimulation, and poor testosterone response to hCG, suggesting hypogonadotropic hypogonadism with poor Leydig cell function. Whole exome sequencing confirmed a BBS2 gene mutation, establishing the diagnosis of Bardet-Biedl Syndrome. This mutation disrupts hypothalamic signaling, leading to the multisystem involvement observed. Over the follow-up period, he reported difficulty with night vision. Conclusion Not all syndromic obesity is immediately apparent— Bardet-Biedl Syndrome should be considered even in the absence of classical features. Marked phenotypic variability often leads to delayed diagnosis, highlighting the need for vigilant clinical suspicion and prompt genetic study to ensure timely recognition. Early recognition is critical, as endocrine and other associated complications can significantly impact long-term health.
Bardet-Biedl Syndrome ; Obesity