Clinical Sub-Dean
Institute of Neurology, University College London, United Kingdom
THEME: HEREDITY AS THE CAUSE OF NEUROLOGICAL DISORDERS- THE EXAMPLE OF EPILEPSY
The most intriguing recent developments in epilepsy seem to be modern reinventions of the 'neurological trait'. Until
recently, it was thought that genes have two copies – one from each parent. However, there may be three or more copies
(duplication) or no copies at all (deletions), known as Copy Number Variations (CNV). The same CNVs seem to underpin
epilepsy and certain neuropsychiatric conditions that are closely associated with epilepsy, such as schizophrenia,
depression, suicide, autism and learning disability. It is possible that 'co-morbidity' is really the manifestation of a
common underlying mechanism – the CNV. These co-morbid conditions may predate epilepsy and thus act as a warning
sign.
Future research should concentrate on genetic networks, rather than single genes, as the underpinnings of groups of
diseases. Networks that are likely to be affected in epilepsy include those underlying synaptic transmission, the
organization of synaptic vesicles, cellular memory and learning. Epistatic (effect of one gene on another) and epigenetic
(effect of non-genetic factors) interactions may occur at different points in time. Waddington's 'epigenetic landscape'
provides a framework to understand the different choice points that may occur in the interaction of genetic and
environmental factors over time, thereby conceptualizing epilepsy as a neurodevelopmental disorder.