Novel Mutation of Aquaporin-2 Gene in a Patient with Congenital Nephrogenic Diabetes Insipidus

Abstract

Abstract. Congenital nephrogenic diabetes insipidus (Cndi) is a rare inherited disease, characterized by an inability of the kidney to concentrate urine in response to vasopressin. Three different inheritance patterns have been described, i.e., the X-linked recessive form associated with arginine vasopressin V2 receptor (AVPR2) gene mutations, the autosomal recessive and dominant forms of Cndi associated with mutations in the aquaporin-2 (AQP2) gene encoding the vasopressinregulated water channel of the renal collecting duct. our case is an 18-year-old male patient who complained of severe polyuria since his infancy. But his developmental and growth status were normal. He was diagnosed as Cndi by water deprivation test and genomic dna sequencing, which revealed high plasma aVP levels but persistently low urine osmolalities to 6 h-water deprivation and the novel missense mutation S216F in exon4 of the AQP2 gene. immunohistochemistry of renal biopsied tissue revealed that most of the aQP2 labeling was seen intracellularly in a dotted pattern in the collecting duct principal cells. Immunoblotting of urine samples revealed significantly decreased urinary excretion of AQP2 (~7% of normal control). Here, we report a new case of Cndi associated with the novel missense mutation of the AQP2 gene.

Characterization of AQP‐2 gene mutation (R254Q) in a family with dominant nephrogenic DI

“…In the presence of active AVP2R in NDI patients, the expectation is a decrease in systolic and diastolic blood pressures, and an increase in heart rate, factor VIII and vWF : Ag. Although concrete results could not always be recorded, any increase in coagulation response should have indicated a normal V2 receptor and be suggestive of a defective AQP2 mechanism 4,5 . Basal levels of factor VIII and vWF factor were elevated by 182% and 200%, respectively, during this desmopressin infusion test.…”

Novel compound aquaporin 2 mutations in nephrogenic diabetes insipidus

“…Interestingly, the patient's height-for-age ratio at age four was within the normal range. Patients with mutations in the AQP2 gene have a short (9) or normal stature (10,11). The response to therapy in this child was notably better than the response of other patients with autosomal-recessive NDI due to AQP2 gene mutations.…”

Investigation into dual modality fiber probe imaging system

“…For diagnosis of diseases like cancer, a small slice of the tissue is taken for biopsy [3][4][5][6][7][8][9][10][11].…”

“…Biopsy is the standard technique applied in medical practice for the examination of cells or tissues. The procedure involves taking a smail sample of tissue from the body (skin [3], liver [4], kidney [5], nerves [6], stomach [7] etc.) and examining it under a microscope or testing with chemicals.…”

“…If we consider fluorescence, the emission intensity from the sample depends upon the photons absorbed by the sample. If the intensity of the incident light has no temporal dependence, the total number of photons absorbed per unit time is given by [103] (5.11) where F is the sample fluorophore concentration which is assumed to be constant and (5 is the photon absorption cross-section. Assuming no self-quenching and stimulated emission, the number of fluorescence photons detected per unit time is given by [103] 1 F = ~¢7JNabs (5.12) n 106 ATTENTION: The Singapore Copyright Act applies to the use of this document.…”