TSC2/PKD1 Contiguous Gene Deletion Syndrome (CGS) has been associated with a more severe kidney phenotype than observed in autosomal dominant polycystic kidney disease (ADPKD), displaying childhood onset and progression to end-stage kidney disease (ESKD) within the first three decades of life. Because recent case reports have suggested a more variable clinical course, we sought to characterize a series of patients with CGS.