This family is made up of several eukaryotic phytanoyl-CoA dioxygenase (PhyH) proteins, ectoine hydroxylases and a number of bacterial deoxygenases. PhyH is a peroxisomal enzyme catalysing the first step of phytanic acid alpha-oxidation. PhyH deficiency causes Refsum's disease (RD) which is an inherited neurological syndrome biochemically characterised by the accumulation of phytanic acid in plasma and tissues [1].

1: Human phytanoyl-CoA hydroxylase: resolution of the gene structure and the molecular basis of Refsum's disease. Jansen GA, Hogenhout EM, Ferdinandusse S, Waterham HR, Ofman R, Jakobs C, Skjeldal OH, Wanders RJ; Hum Mol Genet 2000;9:1195-1200. PMID:10767344

2: Functional expression of the ectoine hydroxylase gene (thpD) from Streptomyces chrysomallus in Halomonas elongata. Prabhu J, Schauwecker F, Grammel N, Keller U, Bernhard M; Appl Environ Microbiol. 2004;70:3130-3132. PMID:15128576