The segregation of metabolic functions within discrete organelles is a hall
mark of eukaryotic cells. These compartments allow for the concentration of
related metabolic functions, the separation of competing metabolic functio
ns, and the formation of unique chemical microenvironments. However, such o
rganization is not spontaneous and requires an array of genes that are dedi
cated to the assembly and maintenance of these structures. In this review w
e focus on the genetics of peroxisome biogenesis and on how defects in this
process cause human disease.