Active clinical trials for "Neurofibromatosis 1"

This program is being offered on a patient by patient basis and will require company, Institutional Review Board/Independent Ethics Committee and Single Patient IND approval.

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.

The purpose of the research study is intended to use specimens (such as tissue) and medical information in the Laboratory of Musculoskeletal Oncology at the Van Andel Research Institute for laboratory research in Grand Rapids, Michigan. Small tissue samples of cutaneous neurofibromas will be collected as part of this research. The samples will help researchers learn more about cutaneous neurofibroma and help them better understand NF1. There are many different types of studies, both now and in the future, that can be done using the specimens they receive. These include using the specimens and information to look for new ways to diagnose and treat Neurofibromatosis Type 1 (NF1). The specimens may be used to study how genes affect health and disease, or how genes affect the way a disease or condition responds to treatment. Some of these studies may lead to new products, such as treatments or tests for diseases. Through this study, we hope to find better ways to understand and treat NF1 in the future.

Neurofibromatosis type 1 (NF1) is a frequent, autosomal dominant disorder caused by heterozygous mutations (intragenic or microdeletion) of the NF1 tumor suppressor gene (chr.17q11.2). One of the clinical features is the development of benign and malignant tumors. The most common benign tumors in these patients are tumors of the peripheral nerve sheath, named neurofibromas (cutaneous, subcutaneous and plexiform). Every NF1 patient has a life time risk of 8 to 13% of developing a malignant peripheral nerve sheath tumor (MPNST) out of a pre-existing neurofibroma. In patients with a NF1 microdeletion (5% of NF1 patients), this risk is even twice as high compared to patients with an intragenic mutation. MPNSTs lead to a bad prognosis for the patient, with an overall five-year survival of less than 25%. To know more about the development and progression of these tumors, they will be screened by microarray comparative genome hybridization (Leuven) and full exome sequencing (Leuven). Further experiments will be done in cooperation (bidirectional) with the foreign labs of Victor Mautner (Germany), André Bernards (USA), Karen Cichowski (USA) and Yuan Zhu (USA). For all these experiments, we will make use of tumoral rest material removed from NF1 patients.

Frequency of constitutional mismatch-repair deficiency among suspected neurofibromatosis type 1 patients without a NF1 mutation Constitutional mismatch repair deficiency (CMMRD) is a rare inherited condition. Individuals with CMMRD have an extraordinarily high risk to develop a malignant tumor in childhood or adolescence. Nearly all known CMMRD patients developed a malignancy within the first three decades of life and most often in (early) childhood. Since early cancer detection improves the chances to survive, these patients should be included from early childhood on in intensive cancer surveillance protocols. Typically patients are diagnosed with CMMRD only when they develop their first malignant tumor. Many children with CMMRD show already before the onset of the first malignant tumor clinical signs that may serve as a signpost of this severe condition. Often CMMRD patient show skin patches of milk coffee-like color, termed café au lait maculae (CALM), which are very typical for a different inherited condition named neurofibromatosis type 1 (NF1). NF1, which is much more frequent than CMMRD, also leads to tumor development. But NF1 tumors are usually benign and NF1 children need different, less rigorous, tumor surveillance programs than CMMRD patients. A child with >5 CALM is suspected of having NF1. However, if this diagnosis cannot be confirmed by identification of the causative genetic alteration (NF1-mutation), CMMRD is one possible, but presumably rare, alternative (= differential) diagnosis. Therefore, human geneticists and pediatricians discuss internationally, whether these children should be tested for CMMRD. Diagnosing CMMRD in this situation would allow offering appropriate cancer surveillance protocols to these patients before they develop their first malignant tumor. However, CMMRD testing in this situation may also cause difficulties. Genetic testing may for instance render an ambiguous result, which can neither confirm nor rule out CMMRD. Such a result would create great uncertainty of the appropriate management of the patient. It would be not clear whether intensive cancer surveillance, that may be very stressful for the patient and the family, should be applied or not. Such potential disadvantages of (with respect to tumor development) predictive CMMRD testing argue more against testing when the chances to identify CMMRD in a patient and consequently achieving a benefit for the patient are low. But currently the frequency of CMMRD patients among suspected NF1 patients without a causative NF1 mutation is unknown. It is the aim of this project to get a reliable estimation on the frequency of the differential diagnosis CMMRD in children with NF1 signs in whom the diagnosis NF1 cannot be confirmed. This information is needed to evaluate and weight the benefits and potential disadvantage of CMMRD testing in these children. To know this frequency is also important for appropriate genetic counseling of at risk children and their parents.

.Neurofibromatosis type 2 is an inherently autosomal dominant genetic disease, but cases of mosaicism or de novo mutation are not uncommon. the prevalence is estimated at 1 / 60,000. the clinical presentation is based on the appearance of tumors in the central and peripheral nervous system. The current average age of diagnosis is around 25 to 30 years depending on the studies. Currently, the diagnostic criteria are based on the ENT, neurological and opthalmological manifestations of the disease. Cutaneous manifestations have been described in these patients. Except now, mucocutaneous manifestations of the disease are not taken into account for depisatage or diagnosis. The purpose of this study would be to identify the different cutaneous and mucosal manifestations in a pediatric population under 15 years of age, and to analyze whether this might be of interest in early detection of the disease in association with other symptoms.

The goal of this project is to get more insight into the (neuro)ophthalmological characteristics of children with neurofibromatosis type 1. This way investigators would like to update the current guidelines for follow up and treatment of optic pathway gliomas. Clinical findings will be compared with the results of Optical coherence tomography (OCT) and MRI (magnetic resonance imaging).

Subtle myocardial deformation abnormalities in asymptomatic nf-1 patients: is cardiac screening needed?