The initial newborn screening (NBS) sample, collected at approximately 30 h of life, revealed a GALT of 18.7 μM (N > 40.0), total galactose of 39.8 mg/dL (N < 15), and galactose‐only of 3.6 mg/dL, suggestive of GALT deficiency with an elevated calculated Gal‐1‐P of 36.2 mg/dL but complicated by a relatively high GALT activity level. The gene discussed is GALT; the disease is hyperinsulinemic hypoglycemia, familial, 4.