Primary hyperoxaluria
(PH) is a rare genetic condition characterized by the overproduction of a
substance called oxalate.
In the kidneys, the
excess oxalate combines with calcium to form calcium oxalate, a hard compound that
is the main component of kidney stones. Deposits of calcium oxalate can lead to
kidney damage, kidney failure, and injury to other organs.
What causes Primary
Hyperoxaluria?
PH is caused by the deficiency of an enzyme that normally prevents the buildup
of oxalate. There are two types of PH, PH1 and PH2, which are distinguished by
the enzyme that is deficient.
People with PH1 have a shortage of a liver enzyme called alanine-glyoxylate
aminotransferase (AGT), where as PH2 is characterized by a shortage of an
enzyme called glyoxylate reductase/hydroxypyruvate reductase (GRHPR). Diagnosis
of PH can now be made by direct gene sequencing and the detection of mutations
in DNA obtained from a cheek swab or blood sample.If this fails, a liver biopsy to measure AGT
and GRHPR activities can be used.
