Primary hyperoxaluria type III is caused by mutations in DHDPSL, which encodes a protein which could synthesize glyoxalate, and activating mutations would increase glyoxalate and then oxalate accumulation
Belostotsky R, Seboun E, Idelson GH, Milliner DS, Becker-Cohen R, Rinat C, et al. Mutations in DHDPSL are responsible for primary hyperoxaluria type III. American journal of human genetics. 2010 ;87(3):392-9.
Available from: http://www.ncbi.nlm.nih.gov/pubmed/20797690
Baylor College of Medicine