For example, Heimler syndrome was recently identified as a very mild form of a peroxisomal biogenesis disorder (Ratbi et al 2015), and D-bifunctional protein (DBP) deficiency (OMIM 261515) has been shown to be one of the possible causes in patients with Perrault syndrome (Pierce et al 2010). This evidence concerns the gene DBP and peroxisome biogenesis disorder.