[Leigh syndrome: case report].

The authors describe for the first time in the Country a case of a 10-year-old female child, assisted at the Ophthalmology Clinic of the Hospital Universitário Clementino Fraga Filho UFRJ, with Leigh's syndrome that is part of a metabolic disease group known as mitochondrial encephalomyopathies. It is an hereditary disease transmitted by a different mode of inheritance: mitochondrial, X-linked recessive and autosomal recessive. The beginning of clinical manifestations is varied and occurs usually in the first two years of life, with progressive and insidious evolution and exacerbation periods. Diagnosis is difficult because pleomorphic presentation, based on clinical findings and complementary study related to mitochondrial production of ATP and cytochrome c oxidase deficiencies. Considering that there is no specific treatment, this is based on a palliative procedure. So, the identification of this syndrome is very important to keep it under control, since its evolution is progressive.