Nearly two
tens of diseases are known to be caused by impairment of several metabolic functions of peroxisomes, or by deficiency in individual peroxisomal
enzymes. With the exception of X-bound
adrenoleukodystrophy, all diseases are based on autosomally recessive type of inheritance and a majority of them are characteristic by specific
neurologic symptoms. The group of diseases in which patients develop a generalised loss of peroxisomal functions includes: Zellweger's
cerebro-hepato-renal syndrome,
neonatal adrenoleukodystrophy,
infantile Refsum's disease, hyperpipecolic acidaemia. Other diseases, such as
rhizomelic chondrodysplasia punctata and
Zellweger-like syndrome are accompanied by a deficiency in several enzymatic activities. X-bound
adrenoleukodystrophy, pseudo-
Zellweger's syndrome,
hyperoxaluria 1, adult form of
Refsum's disease and acatalasaemia are peroxisomal diseases with a deficiency of a single
enzyme. In clinically most severe diseases (generalised loss of peroxisomal functions), the impairment of peroxisomal biogenesis is caused assumedly due to the defect in some of the peroxisomal
membrane proteins. The biochemical findings are brought about by insufficiency in such metabolic functions as oxidation of
fatty acids with very long chains, oxidation of the phytanic and
pipecolic acids, synthesis of
cholesterol,
bile salts and plasmalogenes.
Rhizomelic chondrodysplasia punctata and
Zellweger's syndrome are more moderate forms which are dominantly biochemically manifestant by an impairment in the synthesis of plasmalogenes. Among the diseases characterised by a deficiency in individual peroxisomal
enzymes, most frequent is the X-bound andrenoleukodystrophy which has several clinical phenotypes manifestant in childhood, as well as a clinically less severe form manifestant in adulthood-
adrenomyeloneuropathy. The diagnosis of peroxisomal diseases is performed by use of a wide range of methods (morphological, biochemical, immunochemical and molecular genetic examinations) which enable both postnatal and prenatal diagnostics. (Tab. 1, Ref. 104.)