Therefore, diagnostic ratios of the urinary metabolites of 21-deoxycortisol (PTONE) or 17OHP (PT and 17HP) over glucocorticoid metabolites are invaluable for the diagnosis of CYP21A2 deficiency (13) [Fig. 2A (13–28); Table 2 (13, 26, 29, 30)]. This evidence concerns the gene CYP21A2 and hyperinsulinemic hypoglycemia, familial, 4.