Enfermedades mitocondriales

Clinical Manifestations in Children With Mitochondrial Diseases
Ching-Shiang Chi, MD*†1, Hsiu-Fen Lee, MD†‡1, Chi-Ren Tsai, MS‡§, Huei-Jane Lee, PhD†, and Liang-Hui Chen, MS‡
Mitochondrial diseasescomprise a group of complex and heterogeneous genetic disorders. Variable clinical features present a major challenge in pediatric diagnoses. From January 1984-June 2009, 69 patients were diagnosedwith either syndromic mitochondrial diseases or nonsyndromic mitochondrial diseases. Clinical manifestations, laboratory findings, and histopathologic results differentiating syndromic from nonsyndromicmitochondrial diseases were analyzed by c2 test, with cutoff significance at P = 0.05. The commonest clinical manifestation involved central nervous system signs (88.4%). A comparison of centralnervous system signs in syndromic vs nonsyndromic mitochondrial diseases revealed significant differences in terms of headache, external ocular motility, and apnea (P < 0.05). A comparison of organ systemsrevealed a significant difference for signs of the cardiovascular system. Elevated initial blood lactate levels were evident in 40.6% of patients, and 84.8% produced abnormal results after oral glucosechallenge. Ragged red fibers were observed in 51.6% of patients. The positive rate of mitochondrial gene mutation was 27.5%. Age and disease were directly related: the younger the age at initialdisease onset, the higher the frequency of mortality and morbidity. Notorious variability in the presentation of mitochondrial diseases exists in all pediatric subspecialties. Greater familiarity withthose signs will facilitate more accurate diagnoses. Ó 2010 by Elsevier Inc. All rights reserved. Chi C-S, Lee H-F, Tsai C-R, Lee H-J, Chen L-H. Clinical manifestations in children with mitochondrialdiseases. Pediatr Neurol 2010;43:183-189. Introduction In 1962, the first case of mitochondrial disease to present with nonthyroid-origin hypermetabolism was recognized [1]. Mitochondrial diseases...