Antiquitin deficieny; CDG Type I; Cerebral Folate Deficiency; Cerebrotendinöse Xanthomatose; Glut1 Deficiency; Glycine Encephalopathy / non-ketotic hyperglycinemia; lysinuric protein intolerance; M. Alexander; NCL; Niemann-Pick C; OTC deficiency; PDH deficiency; Pyridoxalphosphat dependent epilepsy; Pyridoxine dependent epilepsy; 5-Hydroxytryptophan deficiency. The gene discussed is SLC2A1; the disease is pyridoxine-dependent epilepsy.