NeuroSURE® Metabolites: Succinyladenosine, Cerebrospinal Fluid (CSF)

CSF Succinyladenosine is useful for diagnosing Adenylosuccinate Lyase Deficiency. This testing may also be used for assessment of Variants of Uncertain Significance (VUS) identified during genetic testing (e.g. Next Generation Sequencing or Capillary Sequencing testing). Succinyladenosine is elevated in adenylosuccinate lyase (ADSL) deficiency and results in succinylpurinemic autism, intellectual disability, and, in some cases, growth restriction associated with muscle wasting and epilepsy. Adenylosuccinate lyase is involved in both de novo synthesis of purines and formation of adenosine monophosphate from inosine monophosphate by catalyzing two reactions in AMP biosynthesis: the removal of a fumarate from succinylaminoimidazole carboxamide (SAICA) ribotide to give aminoimidazole carboxamide ribotide (AICA) and removal of fumarate from adenylosuccinate to give AMP. In the absence of ADSL deficiency, succinyladenosine is either not detected or at very low levels in the CSF. Small elevations of succinyladenosine in spinal fluid have been reported in AICA-Ribosiduria (deficiency of AICAR transformylase) a devastating condition involving profound intellectual disability, epilepsy, dysmorphic features and congenital blindness. Small elevations are also seen secondary to fumarase deficiency.