Leigh syndrome: a rare case report

Abstract

Introduction. Mitochondrial diseases are the most common group of inherited metabolic disorders characterized by defects in energy production, caused by mutation of genes encoded by nuclear or mitochondrial DNA. Leigh syndrome is a progressive neurological disorder, affecting 1:40,000 live births. The purpose. To report a rare progressive neurodegenerative, mitochondrial disorder in a child with seizures, hypotonia, ataxia and psychomotor delay. Material and methods. We report on a case of a 20 months old boy, born at term from non-consanguineous, healthy parents, with an uneventful perinatal history. He had no family history of any genetic or neurological disorder. Results. According to the patient's clinical picture, an inborn error of metabolism was suspected. Blood lactate, LDH and CK-MB were markedly elevated. Amino acid analysis was performed in the blood and urine and a high level of Alanine and deviant Ala/Lys ratio was determined. The electroencephalography revealed dysfunction in cortical structures and low convulsive threshold. Magnetic resonance imaging revealed symmetrical hyperintensity in T2w images in thalamus, mesencephalon, brainstem, medullary tegmentum and cerebellar hemispheres (periventricular), medulla oblongata. Genetic analysis revealed the m.3243A>G mutation in the TL1 gene of the mitochondrial genome. Nijmegen Mitochondrial Disease Criteria Scale: based on clinical signs and metabolic / imaging studies, the patient obtained 8 points, which suggests the presence of a mitochondrial disease. MRI findings of Leigh syndrome – symmetrical hyperintensity in T2-weighted images in thalamus, mesencephalon, brainstem, medullary tegmentum and cerebellar hemispheres (periventricular) and medulla oblongata. Conclusions. The diagnosis of Leigh syndrome should be considered in a child with neurological symptoms whose MRI shows bilateral symmetric hyperintense T2w images of the brainstem and basal ganglia. Further investigations include evaluation of blood gas profile and genetic analysis.