View clinical trials related to Neurofibromatosis Type I.
Filter by:Both Neurofibromatosis type 1 (NF1) and Tuberous Sclerosis Complex (TSC) are highly heterogeneous diseases. Cognitive features seem to vary widely even between family members carrying the same mutation. This phenotypic variability is not well understood, but is generally assumed to be caused by modifier genes which regulate the affected pathways. However, recent studies brought forward an alternative explanation for the phenotypic variability. Post-mortem studies showed that second hit mutations causing loss of the second ('healthy') allele are more widespread than previously believed. These loss of heterozygosity (LOH) mutations cause bi-allelic loss of the disease-linked gene and are known to cause the gross of somatic features in both diseases (like neurofibromas and hamartomas). Hence, it could be the stochastic occurrence of second-hit mutations in the brain are the cause of the variable cognitive phenotypes. To investigate to what extent these LOH mutations in the brain contribute to the phenotype and to what extent this variation is due to genetic modifiers factors is unknown. The investigators therefore propose to elucidate this variability by comparing the correlation of cognitive features of monozygotic twins with NF1 or TSC to healthy twins in the population. If modifier genes are the cause of the variability of cognitive features in NF1 and TSC the investigators expect that the variability in cognitive tests in monozygotic twins is the same as monozygotic twins in the healthy population. However, if the variability is caused by the occurrence of LOH mutations, the investigators expect to have a lower correlation in our monozygotic patients compared to the healthy twins.
Background: Patients with neurofibromatosis type 1 are at increased risk of developing tumors called plexiform neurofibromas (PN) that arise from nerves. These tumors are usually non-cancerous, but they can cause serious medical problems. Sorafenib was recently approved to treat patients with kidney cancer and is now being tested in children with cancer. It affects several pathways thought to be important for the development and growth of PN and may therefore shrink these tumors or slow their growth. Objectives: To determine the highest dose of sorafenib that can safely be given to children and young adults with PN. To identify the side effects of sorafenib in these patients. To study how the body handles sorafenib by measuring the amount of drug in the bloodstream over time To determine how the drug affects blood flow and blood cells and proteins. To determine if sorafenib can shrink or slow the growth of PN. To determine the effects of sorafenib on learning, attention, memory, and quality of life. Eligibility: Patients between 3 and 18 years of age with NF1 who have inoperable PN that can cause significant disability. Design: Patients take sorafenib tablets twice a day in 28-day treatment cycles. They may continue treatment until their tumor grows or they develop unacceptable drug side effects. In this dose escalation study, the dosage is increased with every 3 to 6 children who are enrolled until the highest safe dose is determined. In any case, the dose will not exceed that used in children with cancer. Patients are monitored regularly with physical examinations, blood and urine tests, MRI scans and quality-of-life questionnaires. Patients whose bones are still growing have periodic x-rays of the hips and lower legs to monitor for possible changes in the structure of growing bones. Patients have periodic tests of learning and memory before starting treatment and before cycles 4, 12, 18 and 24. Patients have pharmacokinetic studies to examine how the body handles sorafenib. blood samples are drawn before the first dose of sorafenib and then at 30 minutes, 1 hour, 2 hours, 3 hours, 5 hours, 8 hours, 10 to 12 hours, 24 hours and 30 to 36 hours following the first dose. ...
This study will examine whether the experimental drug R115777 (Tipifarnib) can shrink or slow the growth of plexiform neurofibromas in children and young adults with neurofibromatosis type 1 (NF1) and determine what side effects are related to treatment. Plexiform tumors arise from nerves; the only effective treatment is surgical removal. Often, however, not all the tumors can be removed, because of their number or location. Patients with NF1 have a reduced amount of the protein neurofibromin. Neurofibromin is thought to help control the activity of another protein, called ras, which regulates cell growth. Too little neurofibromin, therefore, may allow for uncontrolled cell growth and tumor formation. R115777 interferes with the function of the ras and other proteins. In test tube and animal studies, R115777 has blocked the growth of cancer cells. This study will examine whether the drug is effective against plexiform tumors. Patients with NF1 and progressive plexiform neurofibromas between 3 and 25 years of age may be eligible for this study. Patients whose tumors can be successfully removed surgically may not participate in this study. Candidates are screened with a medical history and physical and eye examinations, blood and urine tests, and magnetic resonance imaging (MRI). Photographs are taken of tumors visible on the body surface. Study participants are randomly assigned to receive either R115777 or placebo (an inactive substance). They take R115777 or placebo tablets every 12 hours for 21 days, followed by a 7-day rest period. This constitutes one 28-day treatment cycle. Treatment continues for as long as the tumors remain stable or shrink and side effects are tolerable. The treatment is switched (for example, from placebo to R115777) or stopped if the tumors grow or if side effects become unacceptable. Patients (or their parents) keep a record of side effects. For the first 3 treatment cycles, patients have a physical examination and blood tests every other week. Blood tests are also done before starting treatment, and at one time point after at least 14 days of treatment to measure the effect of R115777 on proteins in blood cells. A blood sample is obtained before starting treatment and before cycles 4, 7 and 10 and then after every 6 cycles to measure the level of a substance called nerve growth factor. The analysis of nerve growth factor is used to determine if it can predict which patients might be at risk of developing side effects from R115777.