An Example to a Rare Multisystemic and Challenging Metabolic Disorder: Peroxisomal Disease

Abstract

Objective: Peroxisomal diseases (PDs) are autosomal recessively inherited inborn errors of metabolism (IEMs) that have a wide range of clinical presentations, with variable severity. The aim of this study was to describe cases with various subtypes of PDs with different clinical presentations and to increase the awareness of pediatricians to this metabolic disorder. Material and Methods: The study was conducted in Dr. Sami Ulus Maternity and Child Health Treatment and Research Hospital, division of pediatric metabolism, between December 2020 and January 2021. Patients of whom very long chain fatty acids (VLCFAs) were analysed due to various conditions between January 2020 and December 2020 were retrospectively evaluated. Among patients that VLCFA analyses were performed, 71 tests were found to have abnormal results and 20 of these patients had undergone molecular genetic analysis with the suspicion of PDs. An underlying genetic pathology was detected in 6 patients. Data of patients were obtained from patients files. Results: Six patients were evaluated. Diagnoses of patients were as following: Zellweger spectrum disorders (n=4), rhisomelic chondrodysplasia punctata type 1 (n=1), and AMACR deficiency (n=1). Age of onset of clinical symptoms ranged from the neonatal period to 6 years. Main clinical symptoms were hypotonia, developmental delay and dysmorphic findings. Three patients had cataracts and 5 had sensorineural deafness. Elevated transaminases were detected in 5/6 patients, of whom 4 had abnormal liver function tests. VLCFAs were found to be elevated in all patients. Variants in PEX1, PEX5, PEX6, PEX7, PEX12, PEX 26 and AMACR genes were detected. Patients with liver insufficiency received cholic acid treatment. Conclusion: PDs are very rare IEMs that comprise various subtypes with range of clinical phenotypes with different clinical presentations. Although genetic panel analyses is required for the diagnosis of, VLCFA analysis is a very simple and quick tool for the detection of PDs, and should be included in the screening of patients with visual and hearing impairments, liver disease and dysmorphic findings.