Investigation and treatment of metabolic causes of early onset epilepsy
| Disorder | Investigation | Treatment |
|---|---|---|
| AGAT, l-arginine:glycine amidinotransferase; CSF, cerebrospinal fluid; GAMT, guanidinoacetate methyltransferase; GLUT1, glucose transporter 1; 1H-MRS, proton magnetic resonance spectroscopy. | ||
| Biotinidase deficiency | Trial biotin 5 mg twice daily | Biotin 5–10 mg twice daily |
| Plasma biotinidase activity | ||
| GLUT1 deficiency | CSF glucose <2.2 mM, CSF/plasma glucose <0.5 | Ketogenic diet |
| Red cell glucose transport | ||
| Mutation analysis of SLC2A1 gene | ||
| Serine deficiencies | Reduced fasting plasma serine (and variably glycine) | Serine 200–600 mg/kg/day(glycine 200–300 mg/kg/day) |
| Reduced CSF serine and glycine | ||
| Fibroblast 3-phosphoglycerate dehydrogenase or phosphoserine aminotransferase activity | ||
| Mutation analysis of PHGDH and PSAT1 genes | ||
| Creatine deficiencies | Urine creatine/creatinine ratios, urinary guanidinoacetate/creatinine ratio | GAMT deficiency: creatine 500–2000 mg/kg/day, arginine-restricted diet with ornithine supplementation (100 mg/kg/day). |
| Reduced CSF creatine | ||
| Reduced cerebral creatine plus creatinine (1H-MRS) | ||
| Fibroblast guanidinoacetate methyltransferase activity | ||
| Mutation analysis of GAMT, AGAT and SLC6A8 genes | ||
| Untreated PKU | Plasma phenylalanine | Phenylalanine-restricted diet |
| Mutation analysis of PAH gene | ||