Clinical aspects of renal involvement in Bardet-Biedl syndrome

The Bardet-Biedl syndrome (BBS), which consists of polydactyly, obesity, mental retardation, pigmentary retinopathy and hypogonadism has been known since 1922, but due to the great similarity to the clinical manifestations of the Laurence-Moon syndrome (LMS) there is a considerable terminological confusion in the medical literature. An attempt is made at clarifying the problem. Four children from two families have been observed. There were inter- and intrafamilial variabilities of the expression and severity of the particular features, but retinopathy and structural and/or functional abnormalities were found in 100%. The combination of the two can serve as an easy clinical screening for diagnosis of the disease. Renal involvement is considered to be a cardinal feature of the syndrome. The most common and earliest symptoms are polydypso-polyuria and reduced concentrating ability, which may lead to some diagnostic difficulties, especially in infancy. Three children have end-stage renal disease and two of them are on maintenance haemodialysis, which they tolerate well.