[Molecular analysis of peroxisomal disorders].
[neonatal adrenoleukodystrophy]
Peroxisome biogenesis disorders (PBD) include Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD). They are classified into ten complementation groups. Five pathogenic genes have been identified using different model systems of peroxisome deficient mutants. PAF-1 and 2 were identified from CHO mutants and were responsible genes for PBD group F and C. Human PEX 5, 12 and 1, responsible genes for group 2, 3 and 1, respectively, were cloned by homology search between yeast PEX genes and human genes on the cDNA data base. Adrenoleukodystrophy (ALD), the most frequent peroxisomal disorder, shows phenotypic heterogeneity. Its responsible gene was cloned by positional cloning. It encodes a 75 kDa peroxisomal membrane protein (ALDP) that is a member of the ATP-binding cassette transporter family. There are about 120 different mutations including missense, nonsense and splice mutations, as well as insertions and deletions of a few base pairs. There is no correlation between the clinical phenotype and the ALDP gene mutation. Recently, animal models have been produced by targeted mutation of the PBD and ALD genes. The mouse model should facilitate researches on PBD and ALD, especially those on regulatory factors of their phenotypic heterogeneity and on new therapeutic approaches.
