Polycystic Kidney Disease
...in-point to soft-ball size ii) normal kidneys weigh around 160 g each, while formation of cysts can lead to weights of as much as 38 lbs each iii) it is these extreme intrusions upon the kidneys that can ultimately render them useless b) Cyst formation ( 3 characteristics ) i) cell proliferation: cyst cells reproduce faster than kidney cells ii) cellular secretion: production of fluid for enlarging cyst iii) Abnormal basement membrane upon which cell sits (thicker and less organized) c) While in PKD cysts form mainly in the kidneys, they can also form in the liver, spleen, pancreas, ovaries, large intestine, or walls of blood vessels in the brain. IV. Autosomal-Dominant PKD (ADPKD) a) PKD appears in 2 hereditary forms, in which genes that control cyst formation are altered b) The most prominent kind of PKD is ADPKD, also known as the “adult type” and it is the most potentially lethal genetic disease c) “autosomal-dominant”- If only one parent has the disease then there is 50% chance that their child will have it. d) Also, in ADPKD there is a 10% rate of spontaneous mutation, in which for no known reason gene mutates by itself (it is acquired without being inherited). i) Gene is still dominant and is transferred to offspring in same manner. V. Symptoms of ADPKD a) Symptoms usually occur after the age of 30 in affected individuals, symptoms that include: hematuria, high blood pressure, back/side pain, frequent urinary track infections, and liver and pancreatic cysts. b) Chronic back or side pain is most common problem c) In people with ADPKD high blood pressure affects 60-70% by following mechanism, (If interested) i) cysts intrude on blood vessels of kidneys simulating decreased blood flow which causes a reaction via sensors in nephron (JG apparatus) ii) renin is secreted, which converts angiotensinogen from liver into angiotensin I iii) angiotensin I is converted to angiotensin II by angiotensin converting enzyme (ACE) in lungs, which stimulates vasoconstriction and aldosterone secretion to cause high blood pressure. d) Kidney stones in about 20-30% i) Occur because of abnormal drainage of urine from tubules due to blockage from cysts, and this allows time for crystals to form, causing kidney stones. VI. Diagnosis of ADPKD by physician 1. Family history of PKD reported 2. cysts found inadvertently 3. signs or symptoms noticed 4. Formal diagnosis by ultrasound, computed tomography, magnetic resonance imaging, or a gene linkage study. VII. Autosomal-Recessive PKD a) relatively rare disease that usually causes mortality within the first month of life,...