Table 10: Purine and pyrimidine metabolism disorders involving epilepsy.

DisorderDefective enzyme Biochemical characteristicsSeizure characteristics

Lesch-Nyhan Disease (LSD)hypoxanthine-guanine phosphoribosyl transferase↑ Uric acidPredominantly generalized tonic-clonic, developing in early childhood
Adenylosuccinase deficiencyAdenylosuccinate lyase↑ succinylaminoimidazole carboxamide riboside
↑ succinyladenosine
Neonatal seizures
Severe infantile epileptic encephalopathy