Regarding ADSL, several point mutations have been identified in over 100 cases with varying severity (ranging from fatal neonatal encephalopathy to mild or severe neuronopathic disorders), depending on the ratio of accumulated dephosphorylated SAICAR and AdS (Jaeken and Van den Berghe, 1984; Jaeken et al., 1988; Maaswinkel-Mooij et al., 1997; Kmoch et al., 2000; Mouchegh et al., 2007; Zikanova et al., 2010). The gene discussed is ADSL; the disease is neonatal encephalopathy.