Tuberous sclerosis complex with polycystic kidney disease of the adult type: the TSC2/ADPKD1 contiguous gene syndrome.

Although different diseases, tuberous sclerosis complex and autosomal dominant polycystic kidney disease have been seen in association, the molecular basis of this being the proximity of tuberous sclerosis complex 2 and polycystic kidney disease 1 genes on the same chromosome (16p13.3). Therefore, the classic autosomal dominant polycystic kidney disease renal phenotype may occur in the context of tuberous sclerosis complex disease as a result of large deletions involving both the polycystic kidney disease 1 and tuberous sclerosis complex 2 genes. This is known as the tuberous sclerosis complex 2/autosomal dominant polycystic kidney disease 1 contiguous gene syndrome. The criteria for this condition are fulfilled when renal lesions typical for classic autosomal dominant polycystic kidney disease phenotype are associated with tuberous sclerosis complex phenotype. We present a new case of the sporadic form of this genetic disorder. The diagnosis of tuberous sclerosis complex in this patient was established on the presence of major and minor features, and the diagnosis of ADPKD was based on the presence of numerous large roundish renal cysts lined by a nondescript tubular epithelium. Sporadic cases of autosomal dominant polycystic kidney disease and tuberous sclerosis complex do occur. Molecular analysis was not performed because the patient's parents refused permission.