Dominant polycystic kidney disease is a genetic disorder that affects more than 12 million adults and children, or roughly 1 in 500 people, throughout the world. Also known as simply PKD, dominant polycystic kidney disease is so-named because it is characterized by multiple fluid-filled cysts forming along the nephron region of both kidneys, the portion that filters out impurities. These cysts are comprised of cells that proliferate at a much faster rate than normal kidney cells, leading to an increased number and size of cysts. In fact, the number and size of these cysts eventually becomes proportionate to the size and weight of the kidneys and liver, which suffer inflammation and impaired functioning as a result. Unfortunately, there is currently no cure for dominant polycystic kidney disease, nor is there any treatment.
There are two forms of dominant polycystic kidney disease. The more common form is autosomal dominant polycystic kidney disease (ADPKD). The other form, autosomal recessive polycystic kidney disease (ARPKD) is far more rare, only occurring in about 1 out of 20,000 people. While both forms are inherited, ADPKD carries a 50% risk of passing the disease from parent to child at the time of conception. Otherwise, neither form discriminates in terms of gender, age, or ethnicity.
The majority of patients with ADPKD are affected by a deviation in the 16th chromosome, specifically a mutation of the PKD1 gene. In contrast, only about 15% of patients evidence a mutation of the PKD2 gene, which resides in the 4th chromosome. The former scenario represents a much more serious outcome for the patient, though, since the progression to severe renal dysfunction usually occurs at a much faster rate. Autosomal recessive polycystic kidney disease involves receiving two mutated genes, one from each parent. However, the donating parents usually do not have the disease, nor is there a history of it in the rest of the family.
Another unfortunate aspect about this disease is that there are no early warning signs. Eventually, however, various symptoms will begin to surface. The most common include persistent pain in the side or back, passing blood in the urine, and the formation of kidney stones. Hypertension, or high blood pressure, is another symptom that usually occurs before any signs of kidney impairment arise and occurs more frequently in men.
There are a number of secondary complications that may develop due to the presence of dominant polycystic kidney disease. These include an increased risk of liver disease, cerebral aneurysms, and cardiovascular disease. Some patients experience heart murmurs and palpitations due to a prolapsed valve in the heart. The potential for all of these conditions warrants frequent screening and monitoring.
Although there is no formal treatment for this disease, there are a few proactive measures that patients may undertake to slow its progression. The most important of these is to adhere to a healthy diet and exercise regimen and avoid behaviors that increase the risk of heart disease, such as smoking and excessive alcohol consumption. Likewise, steps should be taken to keep blood pressure in check, including medications, if necessary. Finally, it is essential for the PKD patient to avoid over-the-counter drugs that can further damage the liver and kidneys, such as aspirin, ibuprofen, and naproxen.
