MPO and hyperinsulinemic hypoglycemia, familial, 4: A secondary form of MPO deficiency has been described in various disorders, including lead poisoning, severe infections, neuronal lipofuscinosis, obstructive jaundice, diabetes mellitus, and such disseminated cancers as acute and chronic myeloid leukemia, myelodysplastic syndrome, and Hodgkin’s lymphoma [1,2,4].