Neonatal diabetes mellitus (NDM) is a monogenic form of diabetes that occurs in the first 6 months of life. It is a rare disease, occurring in only one in 100,000 to 500,000 live births. Infants with NDM do not produce enough insulin, leading to an increase in blood glucose. NDM can be mistaken for the much more common type 1 diabetes, but type 1 diabetes usually occurs later than the first 6 months of life. 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 and disappears during infancy but can reappear later in life; this type of NDM is called transient neonatal diabetes mellitus (TNDM). Specific genes that can cause NDM have been identified.
Symptoms of NDM include frequent urination, and dehydration. NDM can be diagnosed by finding elevated levels of glucose in blood or urine. In severe cases, the deficiency of insulin may cause the body to produce an excess of acid, resulting in a potentially life-threatening condition called ketoacidosis. Most fetuses with NDM do not grow well in the womb and newborns 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 improves and may normalize growth and development.
In many cases, neonatal diabetes may be treated with oral sulfonylureas such as glyburide. Physicians may order genetic tests to determine whether or not transitioning from insulin to sulfonylurea drugs is appropriate for a patient. A 2006 study showed that 90% of patients with a KCNJ11 mutation were able to successfully transition to sulfonylurea therapy.