[Glutaric aciduria type I: diagnosis in adulthood and phenotypic variability]

Glutaric aciduria typo I (GA I) is an uncommon metabolic disease with autosomal recessive inheritance. It usually presents in the first years of life and frequently causes movement disorders. Only a few cases have been diagnosed in adulthood. Two siblings who were diagnosed of GA I after a course of more than 20 years are reported here. The elder brother, after 9 months of normal psychomotor development, suffered from an acute encephalopathy with generalized hypotonia and, later on, dyskinetic movements. Throughout the following years severe generalized dystonia developed. The younger brother presented at 16 months with acute encephalopathy, hypotonia and generalized choreoathetoid movements. Cranial computed tomography showed in both patients an slight enlargement of Silvian cisures and diffuse white matter hypodensities. Magnetic resonance imaging performed in the second case disclosed in addition bilateral hyperintensities in putamen and caudate nucleous. At 29 and 24 years of age, respectively, an increased urinary excretion of glutaric and 3-hydroxiglutaric acids was detected in both patients. Glutaryl-CoA deshidrogenase activity in fibroblasts was absent in both. The patients were treated with carnitine and riboflavine, with no response. The present report shows that diagnosis of GA I should be considered in adults presenting a range of movement disorders from childhood.