A Randomized Placebo-Controlled Study of Lovastatin in Children With Neurofibromatosis Type 1

Inclusion Criteria:

* Males or females aged between 8 years and 15 years 11 months at time of enrollment who meet NIH diagnostic criteria for NF1 (Appendix 1)
* Participants must have a full-scale IQ of 70 or above. In cases where there is a statistically significant difference between verbal IQ and performance IQ (.05 level as determined by Table B3 in the WASI manual), participants will be eligible if at least one of these quotients is 70 or above
* Participants must have a cognitive impairment defined as having a score of at least one standard deviation or more below the population mean on one or more of the primary objective outcome measures (i.e., impaired on a measure of visual spatial learning and/or sustained attention)
* Participants must be medically stable
* Participants who are on a stable dose of methylphenidate and/or dextroamphetamines for at least one month prior to screening and who will remain on the same dose for the duration of the study.
* Hepatic function: Participants must have a bilirubin within normal limits and AST and ALT ± 2 times the upper limit of normal as determined by the standards at their institution
* Renal function: Participants must have an age-adjusted normal serum creatinine or a creatinine clearance of greater than 70 ml/m/1.73m2
* Hematologic function: Participants must have an absolute neutrophil count of greater than 1,500, a hemoglobin of greater than 9 gms/dl, and a platelet count of greater than 100,000 on study entry
* Participants must sign all required documents, including informed assent and HIPAA documents
* Female participants of childbearing age should not be pregnant, must have a negative pregnancy test before initiation of treatment, and take appropriate birth control precautions to participate in this study.

Exclusion Criteria:

* Full-scale IQ less than 70; In cases where this is a statistically significant difference between performance IQ and verbal IQ (.05 level), patients will be excluded if both quotients fall below 70
* Individuals that are not cognitively impaired on at least one of the primary objective outcome measures
* Individuals with insufficient English to complete the assessments
* Participants taking psychotropic medication other than methylphenidate and/or dextroamphetamines. These patients are eligible if, as clinically indicated, they cease medication for at least 30 days prior to screening and remain off these medication for the duration of the study
* Participants with intracranial pathology such as epilepsy, diagnosed head injury, hydrocephalus or progressive intracranial tumors (children with asymptomatic or static lesions will be eligible)
* Participants who are pregnant or breastfeeding; Participants who have received any investigational drug, other than sirolimus, within 30 days of initiation of study
* Participants who have recently taken Lovastatin. These participants will be eligible after a washout period of at least three months.
* Participants with significant hepatic, renal or hematologic function as previously defined
* Participants with a history of neuromuscular disease, excluding hypotonias thought to be associated with NF1
* Participants with a clinically significant unrelated illness, which in the judgment of the principal or associate investigator, would compromise the participant's ability to tolerate the medication or potentially interfere with the participant's ability to participate in the required testing
* Low cholesterol (lower limit of a total cholesterol of 90mg/dl)
* Participants who have recently taken sirolimus within three months of enrollment. These participants will be eligible after a washout period of at least three months.