To Determine The Efficacy and Safety of GDC-0449 in Patients With Basal Cell Nevus Syndrome (BCNS)

Inclusion Criteria: The subject: * has had diagnosed at least 10 SEB (of diameter 3 mm diameter or greater on the nose or periorbital skin, 5 mm or greater elsewhere on the face, or 9 mm or greater on non-facial areas excluding the skin below the knees) during the two years before study entry, as documented histologically in physicians' records and/or diagnosed clinically by a Study Investigator at baseline. * meet diagnostic criteria for basal cell nevus syndrome * is willing to abstain from application of non-study topical medications to the skin for the duration of the study, including prescription and over the counter preparations. Subjects will be encouraged to use sunscreen (SPF 15) at least once daily on all exposed skin sites. * is willing to forego treatment of BCCs unless the BCCs are documented by Study Investigators, preferably on two separate visits, except when the PSCP believes that delay in treatment potentially might compromise the health of the subject. * has normal laboratory tests as defined by the following: Normal hematopoietic capacity, Normal hepatic function: AST and ALT greater than or equal to 2x the upper limit of normal (ULN) Total bilirubin within normal range 0.20 mg/dl to 1.50 mg/dl or within 3x ULN for patients with Gilbert's disease Normal renal function: normal serum creatinine or measured creatinine clearance less than 50 mL/minute. Fasting cholesterol greater than or equal to 220 untreated * be willing to not donate blood or semen for th…