A 13‐year‐old girl with severe mental retardation, tapetoretinal degeneration, an extinguished electroretinogram and sensoneurinal hearing loss is described. In early life the diagnosis of Zellweger (cerebro‐hepato‐renal) syndrome was considered because of hypotonia, craniofacial dysmorphia, abnormal liver functions and pipecolic aciduria.
Biochemical studies in fibroblasts from the patient revealed a general peroxisomal dysfunction comparable to the findings in Zellweger Syndrome. As the clinical presentation of this patient is essentially different from that in classical Zellweger patients, who usually die early in life, we recommend the study of peroxisomal functions in all patients with severe mental retardation, tapetoretinal degeneration and sensoneurinal hearing loss.