Treatable fluctuating mental impairment in a patient with Bardet-Biedl syndrome.

Bardet–Biedl syndrome (BBS) is an autosomal recessive disorder characterized by rod–cone dystrophy, polydactyly, central obesity, mental retardation, and hypogonadism. Although many organs are involved in BBS, hyperammonemia caused by portal hypertension has been reported previously in only a single patient. We describe the second such patient with BBS and hyperammonemia, associated with fluctuating mental impairment.