Furthermore, detailed analysis of PXR1 has revealed that mutations in this gene are responsible for complementation group 2 of the peroxisome biogenesis disorders.
The majority of PBDs result from mutation in one of 3 genes that encode for the peroxisomal AAA ATPase complex (AAA-complex) required for cycling PEX5 for peroxisomal matrix protein import.
Genetic complementation testing with over 500 different fibroblast cell lines from patients diagnosed with a peroxisome biogenesis disorder (PBD) identified 11 cell lines with a defect in PEX5.