A Case Of Congenital Nephrogenic Diabetes Insipidus Caused By Variant Of Aquaporin 2 And Literature Review

Water homeostasis is one of critical mechanisms to keep healthy,kidney is to regulate the balance of important organs.Diabetes insipidus(DI)is a condition in which the kidney cells are unable to respond to arginine vasopressin(AVP)and thus fail to concentrate urine,leading to discharge of large volume of unconcentrated urine.DI is characterized by polyuria,compensatory polydipsia,and low specific gravity and hypotonicity of urine.DI can be classified to 4 different types based on the pathological features: Central diabetes insipidus(also known as neurohypophyseal DI),nephrogenic DI,gestational DI,and polydipsic DI.Of these,congenital nephrogenic diabetes insipidus(CDNI)is a rare hereditary renal disorder that is caused by dysfunction of the arginine vasopressin receptor 2(AVPR2)or aquaporin 2(AQP2).The main clinical manifestations for CNDI include polyuria,polydipsia,and persistent low specific gravity of urine,irritability,constipation,growth and mental retardation,and electrolyte disorder(hypernatremia and hyperchloremia).In this reported a rare case of CNDI caused by a Thr108 Met missense mutation of AQP2.In this literature review,we focus on the definition,classification,epidemiology,clinical manifestations,diagnosis,and differential diagnosis of CDNI in order to fully understand the characteristics of this disease.Meanwhile,we discuss the molecular mechanism,principles and methods for conventional treatment,and novel strategies for CNDI treatment.Understanding the nature of CNDI will help early diagnosis of this rare disease.Early diagnosis and intervention are important to prevent organ damage and retardation caused by long-term dehydration in CNDI patients.Although numerous potential therapeutic targets have been reported,further investigation is needed to validate their therapeutic potential and provide personalized treatment for patients with different types of diabetes insipidus.The development ofnew therapeutic strategies,for example,gene therapy,merits for the future investigation and may provide promising therapy for CNDI.Finally,early diagnosis,determining the cause of the DI,and long-term continuous monitoring and management of patients are the keys to prevent disability and mortality caused by DI.