MEN1 and tuberous sclerosis: Boni et al. studied 19 sporadic angiofibromas unassociated with clinically manifested MEN1 syndrome or tuberous sclerosis, and found mutations of the MEN1 gene in two tumors, meaning an A→T transition at nucleotide 517 in exon 2, and a transversion of GG→AA at nucleotide 1184–5 in exon 8.