Clinical and Laboratorial Characteristics of Korean Children with Mitochondrial Respiratory Chain Defect

Abstract

Purpose : The study was carried out to characterized the clinical and the laboratorial features of children with mitochondrial respiratoy chain disorders in Korea. Methods : We retrospectively analyzed the clinical and the loboratorial data of 28 children with significantly low activities in respiratory chain complexes of muscle using spectrophotometry. Results : The mean age was 6.67±4.44 years and the ratio males to female was 1.15:1. Eighteen patients (64.3%) showed defects in Complex I, 8 (28.6%) in Complex VI, 1 (3.6%) in Complex II, and 1 in Complex I and IV. Eight cases (28.6%) were diagnosed with Leigh disease, one with MELAS, Kearns-Sayre syndrome, and Alpers disease retrospectively, but the predominant clinical presentations were a nonspecific encephalopathy (17/28, 60.7%). Epilepsy was seen in 21 (75.0%) patients, while developmental delay in 27 (96.4%) patients. Fifteen out of 28 children (53.6%), clinical symptoms mostly appeared below age of 1 year. The brain MRI showed diffuse cortical atrophy in 18 (64.3%) patients and basal ganglia signal changes in 12 (42.9%) patients. Conclusion : The defects in mitochondrial respiratory chain complexes should be considered in any children with an unexplained neurological condition including even epilepsy.