Primary hyperoxaluria type 2 (PH2)

Primary hyperoxaluria type 2 or PH2 is a rare genetic disorder of glyoxylate metabolism with an autosomal recessive inheritance pattern caused by an accumulation of glyoxylate in different organs. The symptomatology is not as severe as that of primary hyperoxaluria type 1 or PH1, also discussed in tellmeGen.

The prevalence of PH2 is lower than that of PH1 and is estimated at around one case per million population.

The first symptoms usually appear in childhood and include recurrent kidney stone formation, calcium deposits in the kidneys and kidney disease. In more advanced stages of the disease, very high blood levels of oxalate can be reached that would damage other organs and is known as systemic oxalosis.

Detection of oxalate and L-glycerate in urine, analysis of kidney stones, determination of glyoxylate reductase activity in liver biopsy and genetic testing are helpful in the diagnosis of PH2.

Early supportive measures are essential for the maintenance of renal function. The goal of treatment is to minimize calcium oxalate deposits to prevent renal failure, so it is important that patients drink an appropriate amount of fluids and are treated with oxalate crystal formation inhibitor drugs. As the disease progresses, some patients may require intensive dialysis and kidney transplantation. The prognosis, if the disease is not treated, is severe.