Clinical spectrum of Bardet-Biedl syndrome among four Saudi Arabian families.

Bardet-Biedl syndrome is an autosomal recessive disorder characterized by rod-cone dystrophy, postaxial polydactyly, obesity, hypogenitalism, mental retardation, and renal dysfunction. It has both interfamilial and intrafamilial clinical variation. We have studied the clinical spectrum of 11 Saudi Arabian patients from four consanguineous families. Postaxial polydactyly was seen in eight individuals and rod-cone dystrophy in almost all patients. Night blindness and diminished visual acuity manifested at varying ages, beginning as early as 36 months. Obesity was found to be common. Renal anomalies were detected in eight patients (72%) and two of them developed end-stage renal failure at 14 and 15 years of age. We also found an increased prevalence of Hirschsprung's disease among these patients. Hypogenitalism was manifested as micropenis in males and delayed sexual maturation in females. Heart defects were uncommon in our series. In contrast, there was increased susceptibility to develop diabetes mellitus and two of our patients developed diabetes at 15 and 22 years of age.