GRHPR Gene Deletion/Duplication and Full Mutation Analysis, Blood

What This Test Examines

The test looks at the GRHPR gene, which provides instructions for making an enzyme called glyoxylate reductase/hydroxypyruvate reductase. It checks for full gene deletions or duplications (missing or extra copies of parts of the gene) as well as other small changes in the gene's sequence that could affect how the enzyme works.

Why Your Doctor May Order It

This test is usually ordered when a person has signs or symptoms suggesting primary hyperoxaluria, such as recurrent kidney stones, high oxalate levels in the urine, or kidney problems that are not explained by other causes. It may also be ordered when there is a family history of the condition or to confirm a diagnosis after other screening tests.

How the Sample Is Collected

A blood sample is collected from a vein in your arm. The sample is sent to a specialized genetic laboratory, where DNA is extracted and analyzed. Results are typically available after several days to a few weeks, depending on the laboratory.

What the Results Mean

A positive result (a disease-causing change found) can support a diagnosis of primary hyperoxaluria type 2. A negative result makes the condition less likely but may not rule it out completely if other genes are involved. Sometimes a variant of uncertain significance is found, meaning the effect of the change is not yet known. Your doctor or a genetic counselor can explain what your specific result means for you and your family.