Links to various pages of info on Cystinuria!

Definition:
Cystinuria is a disorder characterized by stones in the kidney, ureter, and bladder. It is caused by excessive excretion of certain amino acids (protein building blocks) due to a genetic abnormality. (See also nephrolithiasis).

Cystinuria is an inherited autosomal recessive disorder. The kidneys do not adequately resorb certain amino acids during the filtering process, resulting in excess excretion of these amino acids. The amino acids may precipitate (solids separate from liquids) and form crystals or stones in the kidneys, ureters, or bladder.

The disorder is usually diagnosed after an episode of stones, where analysis of the composition of the stones indicates cystine. Less than 3% of known urinary tract stones are cystine stones.

Cystinuria affects approximately 1 out of 10,000 people. Cystine stones are most common in young adults under age 40.

I am glad to get my brother Gary to write about his personal experiences! Here it is.

My Experience with Cystinuria: By Gary B.
(Let me preface this by saying that I am not crazy about doctors.)

My family doctor never told me that I had it. He just said that my kidney stones were cystine, that they were the hardest to get rid of, and the hardest to stay rid of.

I had been having a lot of pain in my back, and sides, and went to this quack that sent me to have an endoscopy.

She thought I might have colonitis, and since they didn't find anything they said it was probably just irritable bowel syndrome.

I went on for a few more years having the pain until I changed chiropractors.
My new chiropractor insisted on having an x-ray before treating me, which is when they found that my left kidney was almost full of stones, and my right one had a stone the size of a golf ball.

It took two laser surgeries on my left kidney, one laser surgery on my right, and five or six lythotripsy surgeries on the two combined (over the next two years) to get rid of all the stones.

The doctor put me on penicilamine to keep the cystine from crystalizing, and said I would have to stay on it for life.

This started in 2001, and I've been fighting it ever since.

There are several possible side effects to this medicine, but the worst is possible leukemia.

I'm supposed to get x-rays every two or three months to see if they come back, and blood tests every month to see I have cancer yet.)

My story by: Peg S.
My oldest brother Gary, whom is eight years older than I am has Cystinuria. Actually he was diagnosed a few years before me. His doctor did not tell him it ran in families. So it took me longer to be diagnosed because we didn't know. When my doctors started asking me if I had any family members with kidney disease, or stones, I said yes. When I told him they were not the usual calcium stones, he started getting curious. When he asked me if they were cystine stones, I couldn't remember however I told him I'd check, well yes they were. So that started the long line of tests and procedures needed to be certain of a diagnosis of Cystinuria.

If you or any members of your family have repeated kidney stone, be sure to read this info listed at the above links. More later, God bless.

Cystinuria
Pronunciations:
cystinuria
diabetes insipidus
medulla
nephrogenic
penicillamine
polycystic
ureter

Cystinuria is a rare disorder that results in excretion of the amino acid cystine into the urine, often causing cystine stones to form in the urinary tract.

Cystinuria is caused by an inherited defect of the kidney tubules. The gene that causes cystinuria is recessive, so people with the disorder must have inherited two abnormal genes, one from each parent (see Genetics:Inheritance of Single-Gene DisordersFigures). People who carry the gene but do not have the disorder have one normal and one abnormal gene. These people may excrete larger than normal amounts of cystine into the urine, but seldom enough to form cystine stones.

Cystine stones form in the bladder, renal pelvis (the area where urine collects and flows out of the kidney), or ureters (the long, narrow tubes that carry urine from the kidneys to the bladder). Occasionally, kidney failure develops.

Symptoms and Diagnosis

Symptoms usually start between the ages of 10 and 30. Often, the first symptom is intense pain caused by a spasm of the ureter where a stone becomes lodged. The stone may also become a site where bacteria collect and cause a serious infection.

A doctor tests for cystinuria when a person has recurring kidney stones. Cystine crystals may be seen during a microscopic examination of the urine (urinalysis), and high cystine levels are found in the urine.

Treatment

Treatment consists of preventing cystine stones from forming by keeping the concentration of cystine in the urine low. To keep the cystine concentration low, a person must drink enough fluids to produce at least 8 pints (4 liters) of urine each day. During the night, however, when the person is not drinking, less urine is produced and stone formation is more likely. This risk is reduced by drinking fluids before going to bed. Another treatment approach involves taking potassium citrate or sodium bicarbonate to make the urine more alkaline, because cystine dissolves more easily in alkaline urine than in acidic urine. Efforts to increase intake of water and make the urine more alkaline can lead to abdominal bloating, making the treatment difficult for some people to tolerate.

If stones continue to form despite these measures, drugs such as penicillamineSome Trade Names
CUPRIMINE
, tioproninSome Trade Names
THIOLA
, or captoprilSome Trade Names
CAPOTEN
may be tried. These drugs react with cystine to keep it dissolved. CaptoprilSome Trade Names
CAPOTEN
is slightly less effective than the other drugs, but it has fewer serious side effects. Although the treatments are usually effective, there is a fairly high risk that stones will continue to form.

Last full review/revision December 2006 by Peter C. Brazy, MD

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