RESUMO
<p><b>OBJECTIVE</b>To analyze clinical and imaging features and genetic characteristics of Leigh syndrome with emergent pulmonary edema.</p><p><b>METHOD</b>The clinical features and imaging data of 2 cases (1 male, 1 female) seen in Anhui Provincial Children's Hospital from 2012 to 2014 were analyzed and summarized. Venous blood samples were sent to Guangzhou Jinyu Medical Examination Center for genetic analysis. Peripheral blood DNA was extracted and amplified, then sent to a sequencing facility for presence of genetic mutation by comparing with the reference sequence (NC_012920.1).</p><p><b>RESULT</b>(1) The first patient was a 7 months old boy. The second patient was a 7 months and 21 days old girl. They were presented with abnormal respiration and pulmonary hemorrhage required mechanical ventilation. The first patient had a similar attack after 4 months of his birth, whose psychomotor development was normal, and no abnormal neurological findings. The value of blood lactate was 1.58 mmol/L. The value of pyruvic acid was 0.25 mmol/L. The value of cerebrospinal fluid lactate was 6. 4 mmol/L, which was an abnormal increase. The second patient had abnormal nervous system development, which included motor development retardation and hypotonia. The value of blood lactate was 6. 8 mmol/L, pyruvic acid was 0.31 mmol/L. Cerebrospinal fluid lactate was 8.2 mmol/L. (2) Imaging data: chest X-ray revealed double lung effusion. Bilateral caudate nucleus and lentiform nucleus had high signal, and bilateral internal capsule forelimbs were affected in DWI sequence of head MRI. Hemispheres, basal ganglia, cerebral peduncle, cerebellum, pons, and splenium of corpus callosum had multiple abnormal signals in head MRI of the second patient. NAA peak showed significantly reduced lesion area in magnetic resonance blood-flow scanning, and Cho peak increased significantly, which were double lactate-peak. (3) Genetic testing: ATPase6 m.9185 t > C mutation was found in case 1 that was consistent with Leigh syndrome pathogenesis. Hybrid mutations (m. 10191 t > C) in mitochondrial DNA was found in case 2. Two cases with the diagnosis of Leigh syndrome was clear. They were given combined therapy, such as mechanical ventilation, limited fluid to alleviate lung exudation, coenzyme Q10, and L-carnitine. The illness of case 1 relapsed after discharge. But in case 2, there was no improvement. They both died after treatment was given up.</p><p><b>CONCLUSION</b>Neurological symptoms were common in Leigh syndrome, in which acute lung hemorrhage was rarely reported. Timely ventilator support can temporarily save lives, but fatality rate is high and prognosis is poor.</p>