Peroxisomal disorders.

Peroxisomes are complex single-membrane cell organelles found in all cell types except erythrocytes. Peroxisomes have both catabolic and anabolic functions & these functions include the synthesis of plasmalogens, the formation of bile acids, polyunsaturated fatty acids, cholesterol & isoprenoids, & the degradation of very long-chain fatty acids (VLCFA's). Peroxisomes multiply by division of existing peroxisomes & this complex process is regulated by both PEX & non- PEX genes. Peroxisomal disorders are broadly categorised into defects of peroxisomal biogenesis with deficiencies of multiple pathways e.g. Zellweger spectrum or defects affecting single enzymes such as D-bifunctional protein deficiency. Peroxisomal disorders present with a wide spectrum of clinical disease ranging from the severe neonatal Zellweger syndrome with dysmorphic features, neurological abnormalities, hepatorenal and gastrointestinal dysfunction with death typically occurring within the first 6 months of life to adult onset X-linked adrenoleucodystrophy which can be confined only to adrenal insufficiency. [ABSTRACT FROM AUTHOR]