Collection of biomaterial for iPSCs to study the molecular mechanisms underlying monogenic epilepsies

Monogenic variants can be found in up to 40% of people with a rare and complex
epilepsy. A significant portion of monogenic epilepsies include
channelopathies, where a pathogenic variant can result in a gain or loss of
function of voltage- or ligand-gated ion channels leading to a variety of
phenotypes. An example of such a monogenic epilepsy is caused by pathogenic
variants in SCN1A, which is associated with a range of epileptic disorders,
including Dravet syndrome (DS), generalised epilepsy with febrile seizures plus
(GEFS+) and febrile seizures (FS). Approximately 30% of epilepsies are highly
drug resistant, and there is an unmet need for tolerable and effective
treatments that reduce seizure frequency and improve quality of life. Induced
pluripotent stem cells (iPSCs), derived from patients* biomaterial, provide us
with a unique opportunity to study the neurological diseases in relevant human
cell types. iPSCs can be generated into model systems of varying complexities,
from very simple cultures containing only one cell type to neuronal organoid
structures that are able to self-organise into a brain-like structure. For
epilepsies, we currently do not know how relevant the different model systems
are in terms of face and predictive validity. Therefore, a major challenge in
using iPSC-derived models for translational purpose is to identify model
systems that show high face and predictive validity while being as simple,
robust, cheap, and scalable as possible.

We aim to collect blood cells from 40 patients with monogenic epilepsy, with a
preference for patients with a pathogenic variant in SCN1A, reprogram these
cells into iPSCs and use these iPSCs for differentiation into neurons and
neuronal organoids to study the relevance of these models for future testing of
antiseizure medications (ASMs).

Laboratory study, using patient-specific blood for the generation of iPSCs and
neurons/neuronal organoids. These models will be grown on micro electrode
arrays (MEAs) and exposed to ASMs, including cannabidiol (CBD), and other
possible precision treatments, to test the relevance of the model systems.

This study will only be carried out in individuals with a monogenic epilepsy
with variable phenotypes and treatment response, for example, variants in
SCN1A, CDH2, TSC2, RHEB and MTOR. Rare and complex epilepsies are mostly
diagnosed in individuals that are young and/or mentally incapacitated.
Therefore, including subjects with NDD is inherent to the study question. The
results of this study will contribute to an increase in knowledge and
understanding of the underlying mechanisms in epilepsy.
Subjects will be asked to give a one-time blood sample (2x5mL for individuals
with an age of 4 years or older, for between the age of 2 and 4 years old this
will be reduced to 1x 5mL), which can result in pain at the site of
venepuncture and/ or hematoma. The collection of blood cells for the generation
of iPSCs and their subsequent use for neuronal cell culture models does not
give risk for adverse events and/or unsolicited findings, which will be clearly
communicated to the participants in the recruitment phase. The methods used for
the collection of patient material are classified as *procedures with minimal
risk and burden* according to the guideline *Toetsing van Onderzoek met
Minderjarige proefpersonen*.