Uric acid is produced by the breakdown of a compound in your body called purines. Purines play a key role in many processes in your body and comprise a major component of your DNA. The kidneys usually get rid of excess uric acid to maintain low levels in your body. Genetic and acquired conditions can cause high levels uric acid, or hyperuricemia, in your child.
Tests and Diagnosis
Elevated uric acid levels in your child can be diagnosed by blood or urine tests. Blood tests provide a direct measure of circulating levels of uric acid. Uric acid concentrations in urine collected over 24 hours can also be diagnostic. A urine test may be particularly useful in children as it limits blood draws and can diagnose uric acid kidney stones. Diagnosis of genetic disorders contributing to high uric acid levels can be made, based on specific tests for enzyme deficiencies. For instance, a test related to hypoxanthine-guanine phosphoribosyl transferase can help diagnose Lesch-Nyhan syndrome.
Features
Uric acid levels in the blood normally range between 3 and 7 mg/dL. At higher levels, uric acid becomes insoluble and crystallizes. These crystals can be deposited in your child's body, causing problems particularly in their joints and kidneys. Arthritis caused by the buildup of uric acid is called gout.
Causes
The levels of purines in your body directly contribute to uric acid levels. Such factors as the rate of purine production, how quickly purines are broken down, and the amount of purines in the diet can affect uric acid levels in the body. How well the kidney excretes uric acid also contributes to uric acid levels. Certain cancers, including those affecting the bone marrow or blood cells, can also cause high levels of uric acid in children. Exposure to environmental toxins, such as lead poisoning, can increase uric acid levels as well.
Genetic Disorders
The rare genetic disorder Lesch-Nyhan syndrome leads to high uric acid levels in the blood, producing complications including arthritis and kidney dysfunction. Another genetic disorder, phosphoribosylpyrophosphate synthetase superactivity, causes increased production of purines. Degradation of the excess purines in this disorder causes high uric acid levels.
Potential Risks
In addition to the potential complications of high uric acid in your child, including gouty arthritis and kidney problems, uric acid levels have been associated with cardiovascular risk. A review article published in the "Journal of the American Society of Nephrology" in 2006 found a correlation between high blood pressure and uric acid levels in the blood in nearly every clinical study conducted to date. There conclusions strongly suggest uric acid may play a role in the development of essential hypertension in children as well as adults.
