Metabolic Causes of Epileptic Encephalopathy

Table 5

Serine synthesis defects.

Disorder	Epilepsy and neuroimaging features	Response to treatment with; L-serine and glycine
3-Phosphoglycerate dehydrogenase deficiency	Infantile phenotype:	Infantile phenotype:
	(i) intractable seizures	(i) Seizure control or significantly lowered frequency
	(ii) MRI: hypomyelination and delayed myelination	(ii) Increased white matter volume
	Juvenile phenotype:	Juvenile phenotype:
	(i) absence seizures	(i) Seizure control
	(ii) MRI: no abnormalities	(ii) Prevention of neurological abnormalities
Phosphoserine Aminotransferase deficiency	Symptomatic patient:	Symptomatic patient:
	(i) intractable seizures	(i) No clinical response to treatment
	(ii) MRI: generalized atrophy, including cerebellar vermis and pons, white matter abnormalities
	Presymptomatic patient:	Presymptomatic patient:
	(i) MRI: no abnormalities	(i) Prevention of all neurological abnormalities
Phosphoserine phosphatase deficiency	Single case, details not reported	Not reported

Adapted from Pearl [2].