Stem Cells in NF1 Patients With Tumors of the Central Nervous System

Hypothesis: Subjects with NF1 and central nervous system tumors who have aggressive lesions
(including, but not limited to optic pathway gliomas) and/or those with tumors causing
neurologic (including visual) morbidity will manifest unique differences in their stem cells
and stem cell-derived differentiated cells compared to patients with NF1 and central nervous
system tumors who have less aggressive disease and/or those with tumors causing minimal to no
morbidity.

Background and Significance: Optic pathway gliomas (OPGs) are low-grade astrocytic tumors
primarily involving the optic nerve, chiasm and tracts that occur mainly in children. Nearly
20% of children with Neurofibromatosis type 1 (NF1) will develop OPGs, although less than
half will develop vision loss from their tumor.1 These tumors have excellent survival
outcomes, making vision loss the primary morbidity in these patients. Furthermore, OPGs are
inherent to the visual pathway, therefore they are rarely, if ever biopsied. This paucity of
OPG tissue limits our ability to clarify the biologic differences between OPGs that cause
vision loss and those that do not. Low-grade astrocytic gliomas in the other regions of the
brain including the hypothalamus, brainstem and cerebellum can also be found in a subset of
children associated with NF1. These NF1-associated brain tumors can progress and also grow at
variable rates and may cause neurologic dysfunction ranging from severe compromise to little
or no symptomality.

This study seeks to develop stem cells lines in children with NF1-related tumors in the
central nervous system (the optic nerve and those from other brain sites). Stem cells from
these subjects will provide a critical insight into the mechanisms responsible for tumor
progression and symptoms associated with the central nervous system, accelerating the
identification of therapeutic targets.

Preliminary Studies: Three recent research developments make it possible to develop a
patient-specific disease model in a dish (so-called "human disease model in dish") and to
study induced pluripotent stem cell (iPSC)-derived disease relevant cells in an isogenic
background. First, embryonic stem cell (ESC)-like cells, also known as induced pluripotent
stem cell or iPSC, can be generated from skin or blood cells in adult patients. Second,
recent research efforts have started to develop culture protocols that differentiate iPSCs
into a variety of cell types in the central and peripheral nervous system (CNS and PNS),
which are affected in NF1 patients. Third, the CRISPR/CAS9 technology allows to genetically
edit the specific disease genes either by repairing the existing mutant genes or creating new
mutations. In order to position at the forefront of NF1 research, it will be important for
the Gilbert Family Neurofibromatosis Institute (GFNI) at the Children's National Medical
Center to explore these recent exciting research developments, to systematically develop
patient-specific human NF1 disease models, and to provide a tool for drug screening and
evaluation on the individual NF patients.

Design and Methods:

3.1 Study Design Cross-sectional collection of NF1 subjects with tumors in the central
nervous system as documented by MRI.

3.2 Study Visits Subjects will have only one visit to collect the blood sample.

3.3 Study Procedures 3.31 Blood Draw Subjects have 20 ml of whole blood drawn during either
1)their sedation for their clinically indicated MRI (IV already being placed for clinical
purpose) or through the outpatient laboratory.

3.32 Stem Cell Processing Blood collected will be immediately transferred to the stem cell
facility at the National Institutes of Health for processing of the specimens in order to
develop stem cell lines.

3.33 Demographics We will collect the subject's age, gender, race, ethnicity, location of
tumors in the central nervous system on MRI, history of vision loss and other neurological
deficits.

3.34 Statistical Analysis As a first step to establish a stem cell library from a specific
population of NF1 children with nervous system tumors, we will not need statistical analysis
at this stage.

Inclusion Criteria:

- Males or females of any age

- Confirmed diagnosis of NF1

- Willingness to submit blood sample and collect clinical history

- MRI documentation confirming tumor location in the central nervous system.

- For study group d, "Non-NF1 full sibling for control purposes" subject must be a full
sibling of a patient with confirmed diagnosis of NF1 and willing to submit blood
sample and collect clinical history.