Peroxisomal disorder

Peroxisomal disorders represent a class of medical conditions caused by defects in peroxisome functions. This may be due to defects in single enzymes important for peroxisome function or in peroxins, proteins encoded by PEX genes that are critical for normal peroxisome assembly and biogenesis.

Peroxisome biogenesis disorders (PBDs) include the Zellweger syndrome spectrum (PBD ZSD) and rhizomelic chondrodysplasia punctata type 1 (RCDP1). PBD ZSD represents a continuum of disorders including infantile Refsum disease, neonatal adrenoleukodystrophy, and Zellweger syndrome. Collectively, PBDs are autosomal recessive developmental brain disorders that also result in skeletal and craniofacial dysmorphism, liver dysfunction, progressive sensorineural hearing loss, and retinopathy. This results in the over accumulation of very long chain fatty acids and branched chain fatty acids, such as phytanic acid. In addition, PBD ZSD patients show deficient levels of plasmalogens, ether phospholipids necessary for normal brain and lung function. RCDP1 is caused by mutations in the PEX7 gene, which encodes the PTS2 receptor. RCDP1 patients can develop large tissue stores of branched chain fatty acids, such as phytanic acid, and show reduced levels of plasmalogens. Name OMIM Gene ICD 10 Zellweger syndrome PEX1, PEX2, PEX3, PEX5, PEX6, PEX12, PEX14, PEX26 Q87.82 Infantile Refsum disease PEX1, PEX2, PEX26 E80.3 Neonatal adrenoleukodystrophy PEX5, PEX1, PEX10, PEX13, PEX26 E71.331 RCDP Type 1 PEX7 Q77.3 Heimler syndrome PEX1, PEX6