Identification of novel mutations in PEX2, PEX6, PEX10, PEX12, and PEX13 in Zellweger spectrum patients

Mutations in each of the 13 identified human PEX genes are known to cause a peroxisomal biogenesis defect (PBD). Affected patients can be divided into two broad clinical spectra: the Zellweger spectrum, which accounts for about 80% of PBD patients, and the rhizomelia chondrodysplasia punctata (RCDP) spectrum. The clinical continuum of Zellweger spectrum patients extends from Zellweger syndrome (ZS) as the prototype and the most severe entity of this group to neonatal adrenoleukodystrophy (NALD) as an intermediate form and infantile Refsum (IRD) disease as the mildest variant. Characteristic features of ZS patients are dysmorphic features, severe neurological impairment, liver dysfunction, and eye and skeletal abnormalities. Similar but less severe clinical signs are seen in patients with NALD and IRD. In this study ten clinically and/or biochemically well-characterized patients with classical ZS were investigated for defects in all known human PEX genes. We identified two novel mutations in PEX2 (official symbol, PXMP3), two novel mutations in PEX6, two novel mutations in PEX10, one novel mutation in PEX12, and one novel mutation in PEX13.