ADA and hyperinsulinemic hypoglycemia, familial, 4: In this regard, using metabolomic and transcriptomic approaches, dysfunctions of purine metabolism, other than the well-known ADSL deficiency, have been reported in autism spectrum disorders [304,305], such as a significant increase in ADA activity, with a reduction in UA [304], and an increase in hypoxanthine, inosine, and xanthosine [305].