PHGDH deficiency (Monarch Disease Ontology identifier MONDO_0011152) can be described as follows. 3-Phosphoglycerate dehydrogenase deficiency (3-PGDH deficiency) is an autosomal recessive form of serine deficiency syndrome characterized clinically in the few reported cases by congenital microcephaly, psychomotor retardation and intractable seizures in the infantile form and by absence seizures, moderate developmental delay and behavioral disorders in the juvenile form. Also known as: PHOSPHOGLYCERATE dehydrogenase deficiency.