Diabetes insipidus, nephrogenic type 1

Nephrogenic Diabetes Insipidus Type 1
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Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Polyuria, Polydipsia
Complications	Dehydration, Electrolyte imbalance
Onset
Duration
Types	N/A
Causes	Genetic mutation
Risks	N/A
Diagnosis	Water deprivation test, Urine osmolality test
Differential diagnosis	N/A
Prevention	N/A
Treatment	Thiazide diuretics, Low-salt diet, Non-steroidal anti-inflammatory drugs
Medication	N/A
Prognosis
Frequency	Rare
Deaths	N/A

Nephrogenic Diabetes Insipidus Type 1 (NDI Type 1) is a rare genetic disorder characterized by the kidney's inability to concentrate urine, leading to excessive urination and thirst. Unlike Central Diabetes Insipidus, which is caused by a deficiency of the hormone vasopressin, nephrogenic diabetes insipidus results from the kidney's inability to respond to vasopressin.

Pathophysiology

Nephrogenic Diabetes Insipidus Type 1 is primarily caused by mutations in the AVPR2 gene, which encodes the vasopressin V2 receptor. This receptor is crucial for the kidney's ability to reabsorb water in response to vasopressin. When the receptor is non-functional or absent, the kidney cannot concentrate urine, leading to the symptoms of polyuria and polydipsia.

Clinical Presentation

Patients with NDI Type 1 typically present with:

• Polyuria: Excessive urination, often producing large volumes of dilute urine.
• Polydipsia: Excessive thirst, leading to increased fluid intake.
• Dehydration: Due to the inability to retain water, patients are at risk of dehydration.
• Electrolyte imbalance: Loss of water can lead to imbalances in electrolytes such as sodium.

Diagnosis

Diagnosis of Nephrogenic Diabetes Insipidus Type 1 involves:

• Water deprivation test: To assess the kidney's ability to concentrate urine.
• Urine osmolality test: To measure the concentration of urine.
• Genetic testing: To identify mutations in the AVPR2 gene.

Management

Management of NDI Type 1 focuses on reducing symptoms and preventing complications:

• Thiazide diuretics: These can paradoxically reduce urine output in NDI by reducing the kidney's ability to excrete sodium.
• Low-salt diet: Helps to reduce the amount of urine produced.
• Non-steroidal anti-inflammatory drugs (NSAIDs): Can reduce urine output by decreasing renal blood flow.

Prognosis

With appropriate management, individuals with Nephrogenic Diabetes Insipidus Type 1 can lead normal lives, although they must maintain careful control of their fluid intake and monitor for signs of dehydration.

Also see

• Diabetes insipidus
• Central diabetes insipidus
• Vasopressin
• AVPR2 gene