Peroxisomal disorders represent a class of medical conditions caused by defects in
peroxisome
A peroxisome () is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen pero ...
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
Peroxisome biogenesis disorders (PBDs) include the
Zellweger syndrome spectrum (PBD-ZSD) and
rhizomelic chondrodysplasia punctata
Rhizomelic chondrodysplasia punctata is a rare developmental brain disorder characterized by systemic shortening of the proximal bones (i.e. rhizomelia), seizures, recurrent respiratory tract infections and congenital cataracts. The affected in ...
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.
PBD-ZSD is most commonly caused by mutations in the ''PEX1'', ''PEX6'', ''PEX10'', ''PEX12'', and ''PEX26'' genes.
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.
Enzyme and transporter defects
Peroxisomal disorders also include:
References
External links
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{{Peroxisomal disorders
Peroxisomal disorders
Organelles