Three New PAX2 Gene Mutations in Patients with Papillorenal Syndrome

Papillorenal syndrome (PAPRS; Mendelian Inheritance in Man [MIM] 120330) is an autosomal dominant disease characterised by the presence of congenital renal and optic nerve abnormalities associated with mutations of the PAX2 gene. In this article, the authors present four patients with PAPRS who are carriers of three new PAX2 mutations, as well as another patient with a possible non-pathogenic variant of the PAX2 gene. All patients were given a full neurophthalmological examination, and all patients underwent a genetic test for PAX2. Patients 1 and 2 presented with the classic signs of PAPRS: renal disease associated with a congenitally abnormal optic disc, whereas patients 3 and 4 only presented with a congenital optic nerve abnormality and no renal involvement. In patients 1 and 2, the optic nerves were affected by the presence of a central excavation within the optic disc, absence of the central retinal artery, as well as multiple cilioretinal arteries radiating from the periphery of the optic disc. Bilateral optic nerve pits were seen in patient 3, and lastly, in patient 4 there was the presence of superficial gliotic tissue on the left optic disc. All patients presented with a missense mutation in the PAX2 gene, where in patient 4 possibly being only a non-pathogenic variant of the gene. In conclusion, the authors present two patients with classic clinical signs of PAPRS, having two new PAX2 mutations, which until now have not been described in the current literature; another patient with a new PAX2 mutation showing only ocular manifestations of the disease, and lastly, a patient who is a carrier of a variant of the PAX2 gene has a congenitally abnormal optic disc, which is probably not related to PAPRS.