Refsum Disease: An Overview
Refsum disease, originally termed Heredopathia Atactica Polyneuritiformis, is a metabolic disorder characterised by the accumulation of phytanic acid in blood and tissues. Originally described in 1946, its four hallmark findings were: retinitis pigmentosa (RP), peripheral neuropathy, cerebellar ataxia and elevated protein content in the cerebrospinal fluid. Most cases result from variants in the PHYH gene, encoding phytanoyl-CoA hydroxylase, the enzyme responsible for the first step in phytanic acid alpha-oxidation; some cases are also attributed to variants in the PEX7 gene which is involved in transporting this enzyme into peroxisomes.