PNPO and anemia: Other than seizures, patients with PNPO deficiency also exhibit metabolic disorders, such as hypoglycemia, acidosis, and anemia (Clayton et al. 2003; Mills et al. 2005) because PLP is a co-factor required for more than 100 enzymes that function in amino acid metabolism, gluconeogenesis, immune system, and neurotransmitter synthesis (Canzanello et al. 1995; Eliot and Kirsch 2004).