• Gluconeogenic and glycogenolytic enzymes are immature in utero.
• The maximum risk of hypoglycemia is in the first 24 hours of life and definitely not after 72 hours unless the baby is an “at-risk group” baby.
• Glucose dysregulation in newborn (Hypo-/hyperglycemia) is segregated into transitional, transient, permanent and syndromic.
• Transitional hypoglycemia is quite common even in normal babies; resolves within 24-48 hours of life.
• Refractory hypoglycemia accounts for 3-7% of cases of hypoglycemia.
• Causes of refractory hypoglycemia – Congenital hyperinsulinism (CHI), metabolic, endocrine, accelerated starvation and transient.
• Eleven genes have now been implicated in monogenic CHI (ABCC8, KCNJ11, GL UD1, GCK, HADH1, UCP2, MCT1, HNF4A, HNF1A, HK1, PGM1).
• Neonatal hyperglycemia is rare and often transient.
• Neonatal diabetes millitus (NDM) is defined as persistent hyperglycemia occurring in the first 6 months of life that lasts for more than 2 weeks and requires insulin for management. It is rare – 1 in 1,00,000-5,00,000 live births. It is monogenic in origin. More than 10 genes have been identified so far.
• Both CHI and NDM are a very heterogeneous spectrum of glucose dysregulation disorders.
• Genotype characterization not only helps in appropriate treatment but also in prenatal counseling and antenatal diagnosis. This may also have implications on other family members.

All babies suspected to have glucose dysregulation disorder (CHI/NDM) should undergo genetic testing, as appropriate.