Examples include large deletions encompassing TSC2 and PKD1, resulting in a combined phenotype of tuberous sclerosis complex and autosomal dominant polycystic kidney disease [10,11], as well as deletions involving COL4A5 and COL4A6, which cause Alport syndrome with diffuse leiomyomatosis [12]. Here, COL4A5 is linked to autosomal dominant polycystic kidney disease.