Polycystic kidney disease (PKD) is a genetic disorder characterized by the growth of numerous cysts in the kidneys. The kidneys are two organs, each about the size of a fist, located in the upper part of a person's abdomen, toward the back. The kidneys filter wastes and extra fluid from the blood to form urine.
diagnostic (comparative more diagnostic, superlative most diagnostic) 1  of, or relating to diagnosis. 2  characteristic of a particular disease.
A diagnostic test can be thought of as any test used to help diagnose a pathological condition. However, for our text, we will say that a diagnostic test is a test that involves some type of sophisticated diagnostic equipment and/or lab tests. We will not refer to simple blood and lab tests as diagnostic tests.