pediatrics
Peroxisomal Disorders
Zellweger syndrome (ZS), neonatal adrenoleukodystrophy, and infantile Refsum disease (IRD)
These disorders are 3 expressions of a disease continuum, from most (ZS) to least (IRD) severe. The responsible genetic defect occurs in 1 of at least 12 genes involved in peroxisomal formation or protein import (thePEXgene family). Manifestations include facial dysmorphism, central nervous system malformations, demyelination, neonatal seizures, hypotonia, hepatomegaly, cystic kidneys, short limbs with stippled epiphyses (chondrodysplasia punctata), cataracts, retinopathy, hearing deficit, psychomotor delay, and peripheral neuropathy. Diagnosis is suspected when elevated blood levels of VLCFA, phytanic acid, bile acid intermediates, and pipecolic acid are detected and is confirmed by genetic testing. There is currently no specific treatment for these disorders. Management is mainly symptomatic. 