Affiliations: Pediatric Intensive Care Unit, San Rafael Hospital,
Madrid, Spain
Note: [] Correspondence: Alfonso Pérez Palomino, MD, Hospital San
Rafael, c/Serrano 199, 28016, Madrid, Spain. E-mail: [email protected]
Abstract: Mitochondrial disorders, once thought to be relatively rare, are now
thought to be the most prevalent metabolic disease. They represent a challenge
to clinicians, especially in children, in whom clinical presentation and course
show enormous variation. We report a respiratory chain enzyme activity disorder
(complex I, III and IV) in a girl, with a severe presentation since the
perinatal period. An older female sibling had died at the age of 11 months from
an encephalopathy, with a similar clinical presentation. Enzyme activity
disorders could not been disclosed. This association has been described only
rarely. Mitochondrial disorders associated with defects in the respiratory
chain can be attributable to mutations in the mitochondrial genome
(mitochondrial DNA) or the nuclear genome (nuclear DNA). The diagnosis is based
on the presence of clusters of abnormal mitochondria in muscle cells and a
biochemically defined defect in the respiratory chain enzymes or, more
recently, also on mutations in the mitochondrial DNA. In our case muscular
biopsy to assess enzymatic activity of the respiratory chain complexes
disclosed defects in respiratory chain complexes I, III and IV (cytochrome c
oxidase). The patients, as our case, usually present early in life and are more
severely affected than patients with isolated complex deficiencies. Therapy
remains largely ineffective.
Keywords: Mitochondrial disorders, family, clinical features
