Prenatal diagnosis of peroxisomal disorders. Biochemical and immunocytochemical studies on peroxisomes in human amniocytes.

Prenatal diagnoses of peroxisomal disorders, including peroxisome-deficient Zellweger syndrome, isolated deficiency of peroxisomal beta-oxidation enzyme and rhizomelic type chondrodysplasia punctata were investigated by means of the lignoceric acid oxidation assay, indirect immunofluorescence staining and pulse-chase experiments, using cultured amniocytes. Assessment of peroxisomal beta-oxidation activity by means of [1-14C]lignoceric acid oxidation is essential for the diagnosis of a single enzyme deficiency of peroxisomal beta-oxidation with detectable enzyme protein. For the diagnosis of Zellweger syndrome, the absence of peroxisomes was readily determined by immunofluorescence staining of only a few amniocytes. Evidence for abnormal processing of 3-ketoacyl-CoA thiolase leads to the diagnosis of rhizomelic chondrodysplasia punctata. All the fetuses were considered to be normal and the neonates were normal. Use of these methods requires only a small number of amniocytes and will facilitate the prenatal diagnosis of peroxisomal disorders.