Effect of l-Arginine in One Patient with Peroxisome Biogenesis Disorder due to PEX12 Deficiency

Peroxisome biogenesis disorders(PBD) are a heterogeneous group of disorders due to PEX genes mutations, with a broad clinical spectrum comprising severe neonatal disease to mild presentation. Recently, Berendse et al reported an improvement of peroxisomalfunctions with l - argininesupplementation in fibroblasts with specific mutations of PEX1, PEX6, and PEX12 . We report the first treatment by l - argininein a patient homozygous for the specific PEX12 mutation shown to be l - arginineresponsive in fibroblasts. We described the effect of l - arginineon biochemical (decrease of some plasma peroxisomalparameters) and neurophysiological (improvement of deafness) parameters. Some subjective clinical effects have also been observed (no more sialorrhea, behavior improvement). More studies are needed to assess the efficacy of l - argininein some PBD patients with specific mutations.