GSTM1 and hyperinsulinemic hypoglycemia, familial, 4: The G6PD reference values in newborn subjects determined by spectrophotometric assay were as follows: deficiency < 3.03 U/g Hb, intermediate 3.03—8.07 U/g Hb, and normal > 8.07 U/g Hb, whereas that determined by the automated UV enzymatic assay was as follows: deficiency < 7.78 U/g Hb, intermediate 7.78—20.75 U/g Hb, and normal > 20.75 U/g Hb (Fig. 1a-d and Table 2).