They are vesicles with enzymatic activity and the capacity for ATP production, but the reduced amount of Ubiquinol-Cytochrome C Reductase Core Protein 2 (UQCRC2) and Succinate dehydrogenase iron-sulfur subunit (SDH-B) in mitovesicles isolated from a Down syndrome brain suggests an impairment of ATP production in brains derived by trisomic mice [19]. This evidence concerns the gene UQCRC2 and Down syndrome.