have disclosed no financial relationships relevant to this article. This commentary does contain a discussion of an unapproved/ investigative use of a commercial product/device. AbstractNeonatal hyperglycemia has multiple causes, some of which are common (sepsis, stress, phenytoin or glucocorticoid administration) and others of which are more rare, including transient neonatal diabetes and mutations of sulfonylurea receptors, which require molecular diagnosis. Many infants identified with the latter condition may respond well to oral sulfonylurea medications. We describe an infant in whom molecular diagnosis permitted such therapy as well as a new diagnosis for the mother, who had been insulin-dependent for 17 years. In addition to aberrant expression of imprinted genes on chromosome 6q24 for transient neonatal diabetes, molecular diagnosis offers a rationale for oral hypoglycemic agents (off-label use) that may improve the lives of affected infants.Objectives After completing this article, readers should be able to:1. List causes of neonatal diabetes mellitus. 2. Describe the phenotypic features of permanent neonatal diabetes mellitus. 3. Review the gene mutations associated with permanent neonatal diabetes mellitus.

Background Plasma nitrite serves as a reservoir of nitric oxide (NO) bioactivity. Because nitrite ingestion is markedly lower in newborns than adults, we hypothesized plasma nitrite levels would be lower in newborns than in adults, and that infants diagnosed with necrotizing enterocolitis (NEC), a disease characterized by ischemia and bacterial invasion of intestinal walls, would have lower levels of circulating nitrite in the days prior to diagnosis. Methods Single blood and urine samples were collected from 9 term infants and 12 adults, 72 preterm infants every 5 d for 3 wk, and from 13 lambs before and after cord occlusion. Results Nitrite fell 50% relative to cord levels in the first day after birth; and within 15 min after cord occlusion in lambs. Urinary nitrite was higher in infants than adults. Plasma and urinary nitrite levels in infants who developed NEC were similar to those of preterm control infants on days 1 and 5, but significantly elevated at 15 and 20 d after birth. Conclusion Plasma nitrite falls dramatically at birth while newborn urinary nitrite levels are significantly greater than adults. Acute NEC is associated with elevated plasma and urinary nitrite levels.