http://www.creativebiomart.net/description_382721_12.htm

PHYH is a member of the family of iron(II)-dependent oxygenases, which typically incorporate one atom of dioxygen into the substrate and one atom into the succinate carboxylate group. It is expressed in liver, kidney, and T-cells, but not in spleen, brain, heart, lung and skeletal muscle. PHYH has three substrates which are known as phytanoyl-CoA, 2-oxoglutarate, and O2, while its three products are 2-hydroxyphytanoyl-CoA, succinate, and CO2. PHYH converts phytanoyl-CoA to 2-hydroxyphytanoyl-CoA. Defects in PHYH can cause Refsum disease (RD). RD is an autosomal recessive disorder characterized clinically by a tetrad of abnormalities: retinitis pigmentosa, peripheral neuropathy, cerebellar ataxia, and elevated protein levels in the cerebrospinal fluid.