$Unique_ID{BRK03984} $Pretitle{} $Title{Medullary Cystic Disease} $Subject{Medullary Cystic Disease Familial Juvenile Nephronophthisis Renal-retinal Dysplasia } $Volume{} $Log{} Copyright (C) 1986, 1990 National Organization for Rare Disorders, Inc. 226: Medullary Cystic Disease ** IMPORTANT ** It is possible the main title of the article (Medullary Cystic Disease) is not the name you expected. Please check the SYNONYMS listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Familial Juvenile Nephronophthisis Renal-retinal Dysplasia General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Medullary Cystic disease is a diffuse kidney disease, either genetic or congenital in origin, which usually appears in children or young adults (juvenile nephropthisis). It is characterized by a gradual increase of urea and other by-products of protein breakdown in the blood (uremia) due to progressive failure of kidney function. Symptoms Symptoms of Medullary Cystic disease usually begin during the first two decades of life, though the disease has been observed in patients in their sixties. Passing large amounts of urine (polyuria) due to the inability of the kidneys to concentrate the salts dissolved in the urine is often the earliest symptom; this condition is resistant to treatment with vasopressin. Patients commonly pass excessive amounts of sodium in the urine which may be severe enough to require extra sodium intake to prevent extracellular volume depletion. Acidity of the body tissue (acidosis) with or without relatively high chloride in the blood (hyperchloremia) may be present. Retarded growth and evidence of bone disease are common in these children. In many patients, these problems develop slowly over a period of years; the body may, in fact, compensate for the problems so much that they are not recognized until significant uremia symptoms appear later in life due to kidney failure (uremia). Laboratory findings are similar to those in patients with chronic renal failure. Protein in the urine (proteinuria) is minimal or absent, and the urinary sediment is not remarkable. X-rays of the urinary tract demonstrates only small kidneys, but ultrasound and special X-rays (arteriography) may reveal medullary cysts. Causes Medullary Cystic disease is possibly a recessive hereditary disorder. (Human traits including the classic genetic diseases, are the product of the interaction of two genes for that condition, one received from the father and one from the mother. In recessive disorders, the condition does not appear unless a person inherits the same defective gene from each parent. If one receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will show no symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent and will be genetically normal.) Affected Population Fifty percent of patients with Medullary Cystic disease are diagnosed in childhood. Related Disorders Medullary Sponge Kidney is characterized by tubular dilatation or faulty development of the collecting tubules of the kidney. It leads to urinary stasis and kidney stones (nephrocalcinosis). Polycystic Kidney disease is an inherited kidney disorder characterized by many bilateral cysts which cause enlargement of the kidney size, while reducing, by compression, the normal functioning kidney tissue. Therapies: Standard The treatment of Medullary Cystic disease consists of careful management of uremia when it occurs. Diet must be carefully monitored. An increase of caloric intake should be coupled with a reduction in the total content of dietary protein. Sufficient carbohydrates and fats should be consumed to provide energy and prevent the body from metabolizing its own proteins. Therapies: Investigational This disease entry is based upon medical information available through January 1990. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Medullary Cystic Disease, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 National Kidney and Urologic Diseases Information Clearinghouse Box NKUDIC Bethesda, MD 20892 (301) 468-6345 The National Kidney Foundation 2 Park Ave. New York, NY 10016 (212) 889-2210 (800) 622-9010 American Kidney Fund 6110 Executive Blvd., Suite 1010 Rockville, MD 20852 (301) 881-3052 (800) 638-8299 (800) 492-8361 (MD) For information on genetics and genetic counseling referrals, please contact: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References THE MERCK MANUAL 15th ed: R. Berkow, et al: eds; Merck, Sharp & Dohme Research Laboratories, 1987. P. 1631. CECIL TEXTBOOK OF MEDICINE, 18th ed.: James B. Wyngaarden, and Lloyd H. Smith, Jr., Eds.: W. B. Saunders Co., 1988. Pp. 645-8.