Juvenile myoclonic epilepsy does not seem to be recognized as often as it should be, accounting as it does for about one in 10 of those with epilepsy. In addition to the myoclonus, absence seizures and tonic-clonic fits can occur. The interictal EEG shows polyspike and wave discharges, and during the myoclonus, medium to high amplitude 16 Hz spikes. Patients may not be seen by a doctor until a major seizure occurs, and if a history of myoclonus is not obtained, inappropriate treatment may be given. The myoclonus may attributed to clumsiness. The inheritance of the condition is most probably polygenic, although it is claimed that juvenile myoclonic epilepsy may be determined by a single autosomal recessive gene. The most effective treatment is with sodium valproate, and this may have to be life-long. In the presence of major seizures carbamazapine should be used with caution as it may exacerbate minor attacks.