RESUMO
An infant with feeding difficulties, hypotonia, lactic acidemia, and severe hypoketotic hypoglycemia died at the age of 7 months of liver disease. Electron microscopy revealed abnormal mitochondria. Biochemical studies of mitochondrial enzymes in liver showed a decreased activity of complexes I, III, and IV. Mitochondrial DNA (mtDNA) content was reduced in liver 7% of the mean value in control subjects) and in muscle (50%). In kidney, brain, and heart, the mtDNA content was normal. The liver-specific mtDNA depletion syndrome in this patient manifested itself with features of both a respiratory chain defect and a mitochondrial fatty acid oxidation defect. Syndromes involving depletion of mtDNA can be diagnosed only when the activity of the respiratory chain enzymes and the content of mtDNA are investigated in the most affected tissues.
Assuntos
Acidose Láctica/complicações , DNA Mitocondrial/isolamento & purificação , Hipoglicemia/complicações , Falência Hepática/metabolismo , Transporte de Elétrons , Evolução Fatal , Humanos , Lactente , Falência Hepática/enzimologia , Falência Hepática/etiologia , Falência Hepática/patologia , Masculino , Mitocôndrias Hepáticas/enzimologia , Mitocôndrias Hepáticas/genética , Oxirredutases/metabolismoRESUMO
We treated five children with Sjögren-Larsson syndrome. The patients, 5 months to 8 years of age, were given a low fat diet supplemented with medium-chain fatty acids. Plasma octadecanol levels remained unchanged, and skin lesions and neurologic symptoms did not abate. Two patients also failed to respond to dietary supplementation with polyunsaturated fatty acids. We conclude that dietary therapy is usually unsuccessful in patients with Sjögren-Larsson syndrome even when started in early infancy.