Ask the Doctor
Questions about kidney disease? Risk factors? Signs and symptoms? Are you concerned about yourself, a friend or family member? Ask Dr. Spry.
New York, NY
September 22, 1997
It's the most common life-threatening genetic disease and it can cause the kidneys to enlarge from the size of a human fist to that of a football. Affecting more than 600,000 Americans, including famed humorist Erma Bombeck, who died this past year, polycystic kidney disease (PKD) is characterized by the formation of fluid-filled cysts in the kidneys and other organs. PKD leads to chronic kidney failure and the need for dialysis or a kidney transplant in at least half of those who have the disease.
Research Leads the Way
Currently, there is no cure for PKD, but research findings point the way to new hope. The major focus of PKD research is to understand the genetic abnormalities that trigger cyst formation. Two genes that seem to play an important role--PKD1 and PKD2--were identified in 1994 and 1996. According to a study completed this year at Johns Hopkins University School of Medicine, PKD may result when one or more mutations affect the normal interactions of these two genes. Another finding suggests that the kidney cysts develop from individual kidney epithelial cells that have damaged genes.
"These exciting findings should pave the way for the development of improved treatments for PKD within the next several years," says Garabed Eknoyan, MD, president of the National Kidney Foundation.
In the meantime, the most important aspects of managing PKD are treating complications such as high blood pressure and urinary tract infections. If high blood pressure is present, a low-salt diet may also be advised.
PKD Types and Symptoms
There are two main types of PKD. The most common form is called adult PKD, or autosomal dominant PKD, and the less common type is called childhood PKD, or autosomal recessive PKD. The adult type of PKD usually shows up between the ages of 30 and 50, while the childhood form affects babies and young children. Both types of PKD are inherited, but the pattern of inheritance differs. When one parent has autosomal dominant PKD, about half the children may develop the disease. However, for a child to inherit autosomal recessive PKD, both parents must carry the abnormal gene.
Many people in the early stages of PKD are unaware of any symptoms. However, the first noticeable signs may include:
Until science finds a cure, people with PKD can help themselves by following their doctor's advice. Regular checkups are important to detect and treat such complications as high blood pressure and urinary tract infections.
In the light of current research achievements in PKD, hopes for a cure are justifiably at an all time high," says Eknoyan. For additional information about PKD, contact the National Kidney Foundation at (800) 622-9010.