Long-term prognosis in primary hyperoxaluria type II (L-glyceric aciduria).
Primary hyperoxaluria type II (PH-II) or L-glyceric aciduria was first reported by Williams and Smith in 1968 (N Engl J Med 278:233-239, 1968). Deficiencies of D-glycerate dehydrogenase and glyoxylate reductase activity in patients with this disorder leads to increases in urinary oxalate and glycerate excretion. Clinically, PH-II presents in a similar fashion to the more common variant of the disorder, PH-I, with symptoms of calcium oxalate nephrolithiasis. To date, 16 patients with PH-II have been described, and information regarding follow-up is available in only three. We review these reports and present five additional patients from three families, four of whom have been followed closely for more than 20 years. The favorable long-term outcome of our patients over 110 patient-years, as determined by renal function testing and radiographic evaluation, suggests that PH-II may have a more favorable prognosis when compared with the natural history of PH-I. Systematic screening of all PH patients in our practice led to the discovery of five of 30 with PH-II, thus suggesting that this subset population may be more common than originally suspected.