To investigate the molecular mechanisms of tuberous sclerosis ( TSC ) histopathologic lesions , we have tested for loss of heterozygosity the two TSC loci ( TSC 1 and TSC 2 ) and seven tumor suppressor gene containing regions ( TP 53 , NF 1 , NF 2 , BRCA 1 , APC , VHL , and MLM ) in 20 hamartomas from 18 TSC patients . ^^^
We now know that TSC is a hamartomatosis , and thanks to studies of recent years using positional cloning and DNA analysis , we are beginning to understand the biological mechanisms of these disorders which include NF 1 , NF 2 and von Hippel Lindau disease . ^^^