Primary hyperoxaluria
Encyclopedia
Primary hyperoxaluria results in increased excretion of oxalate, with oxalate
stones being common. The oxalalate in these common conditions is derived from dietary sources or is secondary to malabsorption. Primary hyperoxaluria, on the other hand, refers to a specific type of hyperoxaluria that is due to a metabolic defect resulting from a heritable genetic defect.
Oxalate stones in primary hyperoxaluria tend to be severe, resulting in relatively early kidney damage (say teenage, early adulthood), which impairs the excretion of oxalate leading to a further acceleration in accumulation of oxalate in the body.
After the development of renal failure
patients may get deposits of oxalate in the bones, joints and bone marrow. Severe cases may develop haematological problems such as anaemia and thrombocytopaenia. The deposition of oxalate in the body is sometimes called "oxalosis" to be distinguished from "oxaluria" which refers to oxalate in the urine.
Renal failure is a serious complication requiring treatment in its own right. Dialysis can control renal failure but tends to be inadequate to dispose of excess oxalate. Renal transplant is more effective and this is the primary treatment of severe hyperoxaluria. Liver transplantation (often in addition to renal transplant) may be able to control the disease by correcting the metabolic defect.
Oxalate
Oxalate , is the dianion with formula C2O42− also written 22−. Either name is often used for derivatives, such as disodium oxalate, 2C2O42−, or an ester of oxalic acid Oxalate (IUPAC: ethanedioate), is the dianion with formula C2O42− also written (COO)22−. Either...
stones being common. The oxalalate in these common conditions is derived from dietary sources or is secondary to malabsorption. Primary hyperoxaluria, on the other hand, refers to a specific type of hyperoxaluria that is due to a metabolic defect resulting from a heritable genetic defect.
Pathophysiology
The buildup of oxalate in the body causes increased excretion of oxalate, which in turn results in renal and bladder stones. Stones cause urinary obstruction (often with severe and acute pain), secondary infection of urine and eventually kidney damage.Oxalate stones in primary hyperoxaluria tend to be severe, resulting in relatively early kidney damage (say teenage, early adulthood), which impairs the excretion of oxalate leading to a further acceleration in accumulation of oxalate in the body.
After the development of renal failure
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
patients may get deposits of oxalate in the bones, joints and bone marrow. Severe cases may develop haematological problems such as anaemia and thrombocytopaenia. The deposition of oxalate in the body is sometimes called "oxalosis" to be distinguished from "oxaluria" which refers to oxalate in the urine.
Renal failure is a serious complication requiring treatment in its own right. Dialysis can control renal failure but tends to be inadequate to dispose of excess oxalate. Renal transplant is more effective and this is the primary treatment of severe hyperoxaluria. Liver transplantation (often in addition to renal transplant) may be able to control the disease by correcting the metabolic defect.
Classification
There are three main types of primary hyperoxaluria, each associated with specific metabolic defects.| Type | OMIM | Gene |
|---|---|---|
| HP1 | AGXT AGXT Serine—pyruvate aminotransferase is an enzyme that in humans is encoded by the AGXT gene.-External links:* -Further reading:... |
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| HP2 | GRHPR GRHPR Glyoxylate reductase/hydroxypyruvate reductase is an enzyme that in humans is encoded by the GRHPR gene.This gene encodes an enzyme with hydroxypyruvate reductase, glyoxylate reductase, and D-glycerate dehydrogenase enzymatic activities. The enzyme has widespread tissue expression and has a role in... |
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| HP3 | DHDPSL DHDPSL DHDPSL is a human gene.Defects can be associated with primary hyperoxaluria type III.... |