Exploration of the cognitive,adaptive and behavioral functioning of patients affected with Bardet–Biedl syndrome

The aim of the study was to investigate the behavioral phenotype of patients affected with Bardet–Biedl syndrome (BBS). Twenty‐four patients with molecularly confirmed diagnosis of BBS (6–38 years old) were evaluated using standardized neuropsychological tests. Results were compared with normative data. The mean intellectual functioning of participants fell 1.5 standard deviations below normal expectations; though, the majority of participants (75–80%) did not display an intellectual disability. The group's mean performance on most cognitive tasks and all scales of adaptive functioning was significantly weaker than norms. The majority (55–60%) of participants displayed broadly average verbal fluency and auditory rote learning, while 22–40% were severely impaired in the same areas. The majority of participants were severely impaired in perceptual reasoning (53%), attentional capacity (69%), and functional independence (74%). Symptoms associated with Autism were reported for 77% of participants. Behavioral issues were unrelated to intellectual ability but significantly correlated with adaptive functioning. This first neurocognitive evaluation of a molecularly confirmed cohort of BBS patients shows that the majority of patients experience significant difficulties with perceptual intellectual abilities, auditory attentional capacity, adaptive independence, and behavior. The frequency of autism‐related symptoms far exceeds the incidence rate of diagnosed autism in general and warrants further investigations.