Polycystic kidneys is a condition that results from a genetic disorder known as Autosomal Dominant Polycystic Kidney Disease (in rarer cases it is Autosomal Recessive).
Polycystic Kidneys form as a result of a genetic mutation which disrupts development of the kidney cells. This distruption causes the developing kidneys to overproduce, forming cysts. The signs of this disease include a dramatic increase in blood pressure, haematuria (the presence of red blood cells in the urine) and decreased kidney function. It is only known to be caused by genetic factors, though 25% of cases occur spontaneously, where a patent has no family history of the disease.