Get exclusive member benefits & effect social change. Join Today
Nephrogenic Diabetes Insipidus (NDI) is a rare disorder that occurs when the kidneys are unable to concentrate urine. In most people, the body balances intake of fluids with urine excretion. However, people with NDI produce excessive amounts of urine (a condition known as polyuria), which result in insatiable thirst (polydipsia). This balance is regulated by a hormone called vasopressin or antidiuretic hormone (ADH).
Waste and excess water in the blood are filtered through the kidneys, which store liquid waste in the bladder. When fluid intake is low, levels of ADH increase and signal the kidneys to make less urine. Conversely, when fluid intake is high, ADH levels decrease and cause the kidneys to create more urine.
NDI can be acquired through chronic disease or use of certain medications, or inherited (caused by genetic mutations passed down through families). These conditions and mutations interfere with the normal functioning of ADH.
The symptoms of NDI make diagnosis difficult in childhood. To help with diagnosis, doctors use urinary and blood tests. Most cases of NDI are treated with medications.
The cause of NDI can be acquired (through drug use or another disease) or genetic (inherited from parents).
Genetic NDI is caused by a mutation in one of two genes: AVPR2 or AQP2. Mutations are mistakes or damage that causes a change in the genes of a person. According to the National Library of Medicine (NLM), 90 percent of cases of inherited NDI are due to mutations in the AVPR2 gene. (NLM, 2010)
Mutations of the AVPR2 gene are classified as X-linked recessive disorders. This means that the gene defect is on the X chromosome. Because males have only one X chromosome, if they inherit an X chromosome with the gene mutation, they will have the disease. Because women have two X chromosomes, they will only acquire the disease if both X chromosomes have the gene mutation.
A smaller percentage of genetic NDI is caused by mutations in the AQP2 gene, which is primarily autosomal recessive. This means a person must receive a copy of the abnormal gene from each parent in order to develop NDI. In very rare cases, AQP2 is autosomal dominant, meaning that a person only receives one copy of the mutated gene.
NDI can also be acquired. Most acquired forms are from drug use. Medical conditions that affect the minerals of the body or damage the organs can also be linked to NDI.
Drugs that can cause acquired NID include:
Medical conditions that can cause acquired NID include:
The symptoms of NDI vary with age. Infants are severely affected, but symptoms can resemble many other disorders. As children age, symptoms begin to become more recognizable. If a diagnosis is not made, symptoms can become severe enough to cause death.
Symptoms seen in infants can include:
Symptoms in young children can include:
Older children and teenagers can display symptoms that include:
Adults display the most common symptoms, which include:
Rare and fatal symptoms include:
Early diagnosis of NDI is important in preventing life-threatening complications. Tests are ultimately looking for low fasting urine osmolality in the presence of severe water depletion.
Types of urine testing include:
Other tests for NID include:
A water deprivation test (WDT) can be potentially life threatening and is done only under knowledgeable medical teams. The test has the patient refrain from drinking water to see if there is any change in the amount of urine released.
Treatment focuses upon regulating the thirst mechanism and amount of urine released. Medication can be used for successful treatment.
Medications for NID include:
Other treatment options for NID include:
Children who go untreated for NDI can fail to thrive. In severe cases, they may experience mental retardation from the body’s constant dehydration.
Without treatment, NDI can lead to death from dehydration complications. The prognosis is good for those who receive treatment, and medications can help to keep health stable.
Written by: Lydia Krause
Published on: Jul 16, 2012
Medically reviewed on: Dec 15, 2016: University of Illinois-Chicago, School of Medicine
Enter your symptoms in our Symptom Checker to find out possible causes of your symptoms. Go.
Enter any list of prescription drugs and see how they interact with each other and with other substances. Go.
Enter its color and shape information, and this tool helps you identify it. Go.
Find information on drug interactions, side effects, and more. Go.
From companies that meet the high standards of service and quality set by AARP.
Members save 10% on the monthly service charge of qualified AT&T wireless plans.
Members pay $9.50 for Regal ePremiere Tickets purchased online.
Members earn points on select Walgreens-brand health and wellness products.
Join or renew today! Members receive exclusive member benefits & affect social change.