Neonatal diabetes mellitus (NDM) and maturity-onset diabetes of the young (MODY) are the two main forms of monogenic diabetes. NDM occurs in newborns and young infants. MODY is much more common than NDM and usually first occurs in adolescence or early adulthood.
NDM is a monogenic form of diabetes that occurs in the first 6 to 12 months of life. NDM is a rare condition. Infants with NDM do not produce enough insulin, leading to an increase in blood glucose. NDM is often mistaken for type 1 diabetes, but type 1 diabetes is very rarely seen before 6 months of age. Diabetes that occurs in the first 6 months of life almost always has a genetic cause. Researchers have identified a number of specific genes and mutations that can cause NDM. In about half of those with NDM, the condition is lifelong and is called permanent neonatal diabetes mellitus (PNDM). In the rest of those with NDM, the condition is transient, or temporary, and disappears during infancy but can reappear later in life. This type of NDM is called transient neonatal diabetes mellitus (TNDM).
Clinical features of NDM depend on the gene mutations a person has. Signs of NDM include frequent urination, rapid breathing, and dehydration. NDM can be diagnosed by finding elevated levels of glucose in blood or urine. The lack of insulin may cause the body to produce chemicals called ketones, resulting in a potentially life-threatening condition called diabetic ketoacidosis. Most fetuses with NDM do not grow well in the womb, and newborns with NDM are much smaller than those of the same gestational age, a condition called intrauterine growth restriction. After birth, some infants fail to gain weight and grow as rapidly as other infants of the same age and sex. Appropriate therapy may improve and normalize growth and development.