SERPINA7 and hyperinsulinemic hypoglycemia, familial, 4: Since 1995, this program has consisted of a three-step approach, with T4 measurement in all newborns as the first step, TSH measurement in the lowest 20% of T4 concentrations, and thyroxine-binding globulin (TBG) measurement in the lowest 5% to prevent false-positive results due to TBG deficiency [6,31].