Abstract
Serine deficiency disorders are rare causes of seizures in infants and children caused
by a genetic defect in one of the three genes coding for the L-serine biosynthesis
pathway enzymes. A wide phenotypic spectrum can be observed in patients with serine
deficiency disorders ranging from a lethal disorder with multiple congenital abnormalities
to a congenital microcephaly and intractable seizures presenting shortly after birth
or a relatively mild phenotype with childhood absence seizures. Serine deficiency
disorders can be diagnosed by cerebrospinal fluid and plasma amino acid analysis or
by mutation analysis of the three genes including phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1) and phosphoserine phosphatase (PSPHD). Prompt recognition of affected patients is important, since serine deficiency disorders
are treatable causes of seizures. There is a very strict window-of-opportunity to
prevent developmental delay in patients with infantile and juvenile onset of phenotypes.
In this paper, we present an overview of the clinical phenotypes associated with serine
deficiency disorders presenting in infancy and childhood.
Keywords
Serine deficiency - 3-PGDH deficiency - PSAT deficiency - PSP deficiency - seizures
- microcephaly - global developmental delay - L-serine
