TSC2/PKD1 contiguous gene syndrome: a report of 2 cases with emphasis on dermatopathologic findings

The association of tuberous sclerosis complex (TSC) and autosomal dominant polycystic kidney disease (ADPKD), termed TSC2/PKD1 contiguous gene syndrome, is a result of molecular defect demonstrating by deletion disrupting TSC2 and PKD1. Dermatopathology of this syndrome has never been addressed. We report 2 sporadic cases form of TSC2/PKD1 contiguous gene syndrome, with emphasis on dermatopathologic findings. Both patients presented with a typical phenotype of TSC and early-onset renal polycystic requiring kidney transplantation in one of the patients. Of a total of 13 cutaneous lesions studied, there were 7 facial angiofibromas, 2 shagreen patches, 1 periungual fibroma, 1 hypopigmented macule, 1 epidermoid cyst, and 1 intradermal melanocytic nevus. The histological features were basically similar to those occurring in TSC, but some unusual features were identified. In both patients, deletions in the region of TSC2 and PKD1 were revealed performing by multiplex ligation probe amplification test. It is concluded that the histopathological features of skin lesions in this syndrome are similar to those encountered in TSC. Clinical awareness and appropriate molecular investigation of TSC2/PKD1 contiguous gene syndrome is necessary in all patients with a typical phenotype of TSC in infancy, adolescence, or adult age, because of severity of the renal alterations.