ESPE Abstracts

Introduction: Bardet-Biedl syndrome is a rare autosomal recessive disease, characterized by rod-cone dystrophy, truncal obesity, left foot polydactyly, cognitive impairment, male hypogonadotrophic hypogonadism, female genitourinary malformations, and renal abnormalities. The authors present 3 cases of Bardet-Biedl syndrome diagnosed during pediatric age.

Case description: Case1: A 3-year-old girl with a family history of consanguinity was diagnosed with Bardet-Biedl syndrome at the age of 22 months due to the presence of left foot polydactyly, bilateral foot brachydactyly, truncal obesity, developmental delay and left hydronephrosis. Genetic testing was positive for a homozygous mutation in the BBS7 gene. Her anual ophtalmologic evaluation has been showing the presence of astigmatism with no signs of rod-cone dystrophy so far. Post-axial polydactyly was corrected at the age of 8 months. She currently maintains a regular follow-up in the hospital, with nutritional support and speech and occupational therapy.

Case 2: A 12-year old female adolescent with obesity, polydactyly of both feet, clinodactyly of the fifth finger, bilateral foot syndactyly and developmental delay with positive genetic testing was diagnosed at the age of 2 years with Bardet-Biedl syndrome. A family history of consanguinity was present. Apart from an episode of neuroblastoma at the age of 6 months, that was resected at the age of 11 months, she was diagnosed with severe rod-cone dystrophy with macular involvement when she was 7 years old. Due to the progressive and rapid deterioration of her visual acuity, she is currently in need of a system of visual amplification in her daily activities.

Case 3: A 13-year-old male adolescent was referred to the pediatric external consultation due to truncal obesity, severe rod-cone dystrophy with tunnel vision, polydactyly and syndactyly of both hands and feet, hypogonadism and developmental delay. Genetic testing revealed a mutation in the BBS1 gene. Over the course of his follow-up, he developed hepatic esteatosis and dyslipidemia requiring oral medication. He maintains a regular follow-up in the nephrology external consultation due to the presence of nephrocalcinosis and the suspicion of the presence of a medullary sponge kidney.

Conclusion: As shown by our case series, Bardet-Biedl syndrome has a significant interfamilial variation. There is currently no cure for Bardet-Biedl syndrome; patients require a symptomatic and preventive approach and a close multidisciplinary follow-up.