Lafora disease typically starts between ages 12 and 17 years, after a period of apparently normal development. Lafora disease-associated mutations are scattered all along the coding regions of the EPM2A and NHLRC1 genes, but also accumulate in discrete spots of high recurrence. The main seizure types in Lafora disease include myoclonic seizures and occipital seizures, although generalized tonic-clonic seizures, atypical absence seizures, and atonic and complex partial seizures may occur. Studies of the combined mutation detection frequency of sequence analysis in EPM2A and NHLRC1 reveal that between 88% and 97% of mutations in these two genes can be detected using sequence analysis alone. Antiepileptic drugs have a major effect against generalized seizures, sometimes controlling seizures for many months. Valproic acid is the traditional antiepileptic treatment for Lafora disease because it is a broad-spectrum drug that controls both the generalized tonic-clonic seizures and myoclonic jerks.