Abstracts

The etiology of photosensitivity (PPR) is genetically determined and a number of genes are likely to be involved. Recently, significant evidence for linkage was found at 7q32 and 16p13 in PPR families with a prominent myoclonic epilepsy background. Whether specific genes are related with a specific PPR phenotype or with specific seizure type is still unresolved. Here, we described 37 parent-child trios of Greek origin selected on the presence of PPR in at least two awake-sleep-wake video-EEG recordings. The IPS was done in accordance to the European consensus standard technique. The diagnostic of seizures and syndromes was based on a detailed history, observation of (un)provoked seizures during the EEG recording and a consensus among three epileptologists. Nearly all patients were IGE with an age of onset between 8-13 years. Myoclonic and absence seizures were the most frequently observed provoked seizure types and this dichotomy remained consistent within the individuals in repeated records. It seems, therefore, valid to take into account both the EEG phenomena (PPR) and the predominant seizure type in further genetic studies with large series of patients. The identification of susceptibility gene(s) for PPR may guide us to unravel the different epileptogenic pathways (thalamo-cortical [italic]vs.[/italic] neocortical) underlying these seizure types.