Laboratory for Molecular Diagnostics
Center for Nephrology and Metabolic Disorders

Aquaporin 2

Mutations of this gene are responsible for autosomal recessive and dominant nephrogenic diabetes insipidus.

Gene Structure

The gene encoding the water channel aquaporin 2 is located on chromosome 12 (12q13) and spans about 8.1kb. It consists of 4 exons, all of them translated.

Expression

This water channel aquaporin 2 shows the same distribution as the arginine vasopressin receptor. In kidney's collecting duct both molecules regulate ADH dependent water excretion.

Phenotype

The phenotype of AQP2 mutations includes nephrogenic diabetes insipidus either autosomal recessive or dominant.

Gene Regulation

Aquaporin 2 trafficking from cytoplasmic vesicles to the apical membrane is stimulated by cGMP. Phosphorylation of serin at 256 is essential. Signal transduction can be initiated by arginine vasopressin (ADH), atrial natriuretic factor (ANP) or nitric oxide (NO).

Genetests:

Clinic Method Carrier testing
Turnaround 5
Specimen type genomic DNA
Clinic Method Genomic sequencing of the entire coding region
Turnaround 20
Specimen type genomic DNA
Clinic Method Massive parallel sequencing
Turnaround 25
Specimen type genomic DNA

Related Diseases:

Nephrogenic diabetes insipidus
AQP2
AVPR2

References:

1.

Nguyen MK et al. (2003) Molecular pathogenesis of nephrogenic diabetes insipidus.

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2.

Fujiwara TM et al. (2005) Molecular biology of hereditary diabetes insipidus.

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3.

Noda Y et al. (2005) Trafficking mechanism of water channel aquaporin-2.

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4.

Gade W et al. (2006) A brief survey of aquaporins and their implications for renal physiology.

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Update: Sept. 26, 2018