Table 1.

Metabolic disorders presenting with seizures.

Amino acids metabolic disorders

•Serine deficiency •Glycine encephalopathy •Maple syrup urine disease •Urea cycle disorders •Organic acidemia •Sulfite oxidase deficiency •Phenylketonuria

Disorders of energy metabolism

•Mitochondrial diseases •Glucose transporter type 1 deficiency •Guanidinoacetate methyltransferase deficiency •Fatty acid oxidation defects •Disorders of gluconeogenesis •Glycogen storage disorders

Cofactor-related metabolic disorders

•Pyridoxine-dependent epilepsy •Pyridoxal phosphate-responsive epilepsy •Early-onset vitamin B6-dependent epilepsy •Cerebral folate deficiency •Methylenetetrahydrofolate reductase deficiency •Molybdenum cofactor deficiency •Biotinidase deficiency •Holocarboxylase synthetase deficiency

Purine and pyrimidine metabolic disorders

•Lesch-Nyhan syndrome •Adenylosuccinate lyase deficiency •Dihydropyrimidine dehydrogenase deficiency •Dihydropyrimidinase deficiency

Peroxisomal and lysosomal disorders

•Zellweger spectrum disorder •Gaucher disease type 2 and 3 •Niemann-Pick type C •Metachromatic leukodystrophy •Neuronal ceroid lipofuscinosis •GM1 and GM2 gangliosidosis •Sialidosis

Congenital disorders of glycosylation