ABSTRACT:The autosomal recessive Zellweger syndrome spectrum (ZSS) disorders comprise a main subgroup of the peroxisome biogenesis disorders. The ZSS disorders can be caused by mutations in any of 12 different currently identified PEX genes resulting in severe, often lethal, multi-systemic disorders. Defects in the PEX6 gene are the second most common cause for ZSS disorders. The encoded protein PEX6 belongs to the AAA ATPase family and contains two AAA cassettes and an AAA protein family signature. The PEX6 gene consists of 17 exons and previously mutations in the PEX6 gene were found to be scattered over all exons. We developed a post-PCR high-resolution melting (HRM) curve assay to scan the PEX6 gene for potential sequence variations followed by selective sequencing to identify these. We analyzed the PEX6 genes of 75 patients assigned to the PEX6 complementation group. We identified a total of 77 different mutations of which 47 mutations have not been reported previously, and 14 polymorphic variants.