Polycystic Kidney Disease - Types - Autosomal Dominant

Autosomal Dominant

Autosomal dominant polycystic kidney disease (ADPKD) is the most common of all the hereditary cystic kidney diseases with an incidence of 1 to 2:1,000 live births. Studies show that 10% of end-stage renal disease (ESRD) patients being treated with hemodialysis in Europe and the U.S. were initially diagnosed and treated for ADPKD. ADPKD does not appear to demonstrate a preference for any particular ethnicity.

ADPKD is characterized by progressive cyst development and bilaterally enlarged kidneys with multiple cysts. There are three genetic mutations in the PKD-1, PKD-2, and PKD3 gene with similar phenotypical presentations. Gene PKD-1 is located on chromosome 16 and codes for a protein involved in regulation of cell cycle and intracellular calcium transport in epithelial cells, and is responsible for 85% of the cases of ADPKD. A group of voltage-linked calcium channels are coded for by PKD-2 on chromosome 4. PKD3 recently appeared in research papers as a postulated 3rd gene. At this time, PKD3 has not been proven. Fewer than 10% of cases of ADPKD appear in non-ADPKD families.

Cyst formation begins in utero from any point along the nephron, although fewer than 5% of nephrons are thought to be involved. As the cysts accumulate fluid, they enlarge, separate entirely from the nephron, compress the neighboring renal parenchyma, and progressively compromise renal function.

Under the function of gene defect, epithelial cells of renal tubule turn into epithelial cells of cyst wall after phenotype change, and begin to have the function of secreting cyst fluid, which leads to continuous cysts enlargement.