Polycystic kidney disease, which is sometimes referred to as polycystic kidney syndrome, is a genetic disorder that causes sacs of fluid to grow on the kidneys. When these sacs grow too large, the kidneys can become damaged. Polycystic kidney disease ranges in severity from mild cases with no symptoms to severe cases that result in eventual kidney failure.
Definition
According to the National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC), there are two types of polycystic kidney syndrome. Austosomal dominant polycystic kidney disease is the most common form of the condition. Autosomal recessive polycystic kidney disease is rare. Both types of polycystic kidney disease cause numerous cysts to form on the kidneys. The Digital Urology Journal indicates that between 1 in 400 and 1 in 1,000 people in the United States are affected by this condition.
Causes
According to physicians from Milton S. Hershey Medical Center School of Medicine, polycystic kidney syndrome is caused by a genetic defect. In the autosomal dominant form of the disease, the affected child inherits just one PKD gene from a parent. In the autosomal recessive form of the disease, the affected child inherits two genes for PKD. The autosomal recessive form of polycystic kidney syndrome is much more severe than the autosomal dominant form.
Signs and Symptoms
Information from the American Academy of Family Physicians indicates that the signs and symptoms of polycystic kidney syndrome include abdominal pain, blood in the urine, flank pain and recurrent kidney infections. Physicians from Milton S. Hershey Medical Center School of Medicine also associate kidney stones, hernia, brain aneurysm, anemia and heart murmur with polycystic kidney disease. In infants with this condition, the ears appear floppy and there are folds of skin around the eyes. Infants with PKD also may have a pointed nose and small chin.
Diagnosis
According to NKUDIC, the autosomal dominant form of polycystic kidney syndrome is usually diagnosed by ultrasound, CT scan or MRI. Cysts of 1/2 inch or greater can be seen on these diagnostic scans. MRI can be used to monitor the growth of kidney cysts, allowing doctors to track how the disease is progressing. Genetic testing for mutations in the PKD1 and PKD2 genes can also lead to a diagnosis of autosomal dominant polycystic kidney syndrome. Fetuses and infants with autosomal recessive PKD may not have developed large cysts, so ultrasound of the kidneys and the liver are used to determine whether enlarged kidneys and abnormal scarring are present.
Treatment
There is no treatment for polycystic kidney disease, and the growth of cysts cannot be stopped once it has started. However, treatment is available for the symptoms of PKD. Milton S. Hershey Medical Center School of Medicine physicians advise people with polycystic kidney syndrome to control their blood pressure to reduce the workload of the kidneys. This is accomplished with medications and a low-sodium diet. Anemic PKD patients may be given iron supplements. Chronic kidney infections may be treated with antibiotics to prevent further kidney damage. If kidney failure develops as a result of PKD, kidney dialysis or kidney transplant may be necessary.
