Through extensive investigation of the sequence of Phytanoyl-CoA dioxygenase containing 1 isoform a, details regarding its evolutionary history, functions and structure have been discovered. The protein has been found to be a catalytic enzyme for the alpha oxidation of phytanic acid, a long chain fatty acid often found in the human diet. Evolutionary analysis has shown that the gene is well conserved throught the species in particular fungi and animals which also consume phytanic acid. Many comparisons have been made between the structure of the dioxygenase and a the phytanoyl-CoA hydroxylase, whose structure has been previously determined, with particular emphasis on the relevant binding and target sites. Investigation of this gene is particularly pertanent as mutations have been found to cause Refsum's disease due to the build up of phytanoyl-CoA and further knowledge of its actions may be useful to help understand treatment and prevention the disease.