[The clinical utility of genetic testing in epilepsy].

We summarize those epilepsies, in which genetic testing has clinical significance. Different types of genetic tests are presented. Na-channel epilepsies include different clinical entities, the exact genetic diagnosis is relevant in the prognosis, genetic counseling, as well in the therapeutic decision--as Na-channel blockers may worsen them. Molecular genetic tests are available for most of the malformations of cortical development, important for genetic counseling and prenatal diagnosis. Molecular genetic testing of progressive myoclonic epilepsies, which may be difficult to differentiate clinically is almost complete. For some neonatal/infantile epileptic encephalopathies, for most of the neurometabolic disorders, molecular genetic tests are available, so are cytogenetic tests for chromosomal abnormalities accompanied with epilepsy. The clinical significance of the genetic diagnostic of rare, focal inherited epilepsies is limited, their importance is mostly in epilepsy pathophysiology research. The genetic background of the common idiopathic generalized epilepsies is unrevealed so far.