SNP Shot: Genomic Insights

Renal hypouricemia is a kidney disorder characterized by abnormally low levels of urate in the blood. Urate, a natural waste product from the body's metabolism, typically functions as an antioxidant in the bloodstream, protecting cells from damage caused by free radicals. The body normally eliminates excess urate through urine to prevent toxicity from high levels.

Individuals with renal hypouricemia have very little urate in their blood because their kidneys excrete too much urate into the urine. Many people with this condition experience no noticeable symptoms. However, some individuals develop kidney-related problems, such as exercise-induced acute kidney injury after intense physical activity. This can cause side and lower back pain, as well as nausea and vomiting, lasting for several hours.

Due to the excessive excretion of urate through the kidneys, people with renal hypouricemia are more likely to develop kidney stones (nephrolithiasis) composed of urate crystals. These stones can damage the kidneys and cause blood in the urine (hematuria). In rare cases, renal hypouricemia can lead to life-threatening kidney failure.

Inheritance:

This condition is usually inherited in an autosomal recessive manner. This means that both copies of either the SLC22A12 or SLC2A9 gene in each cell must have mutations for the condition to manifest. Individuals with autosomal recessive conditions inherit one mutated copy of the gene from each parent, who are typically carriers but do not exhibit symptoms of the condition. Occasionally, individuals with a single SLC2A9 gene mutation may have reduced urate levels, although these levels are typically not as low as those with mutations in both gene copies and may not cause any symptoms. Rarely, carriers with one mutated gene copy may develop urate kidney stones.