Background and design: Peroxisomal deficiency has been described in a number of syndromes characterized by chondrodysplasia punctata, including the Conradi-Hünermann (C-H) syndrome. Because of overlapping clinical features of X-chromosome inheritance, ichthyosis, and limb-reduction defects in C-H and CHILD (congenital hemidysplasia with ichthyosiform erythroderma and limb defects) syndromes, we examined peroxisomal content using diaminobenzidine cytochemistry and peroxisomal functions in fibroblasts from involved vs uninvolved skin of CHILD syndrome.
Results: Fibroblasts from involved skin of a patient with CHILD syndrome accumulated cytoplasmic lipid, visualized with the fluorescent probe, nile-red. Ultrastructurally, fibroblasts of involved skin of CHILD syndrome accumulated lamellated membrane and vacuolar structures. By diaminobenzidine ultracytochemistry, fewer peroxisomes were present. Moreover, the activities of two peroxisomal enzymes, catalase and dihydroxyacetone phosphate acyltransferase, were decreased (approximately 30% of normal). However, peroxisomal oxidation of very-long-chain and branched-chain fatty acids was preserved. Moreover, plasma very-long-chain fatty acids, plasma phytanic acid, and erythrocyte plasmalogen content were normal.
Conclusions: The CHILD, C-H, and rhizomelic chondrodysplasia punctata syndromes are all characterized by ichthyosis, chondrodysplasia punctata, and limb defects, as well as peroxisomal deficiency. Thus, these syndromes may be related pathogenically. Because peroxisomes are involved in prostaglandin metabolism, peroxisomal deficiency may directly contribute to the previously reported alterations in prostaglandin metabolism in fibroblasts of involved skin of fibroblasts.