Secondary <scp>CoQ<sub>10</sub></scp> deficiency, bioenergetics unbalance in disease and aging
Plácido Navas, María V. Cascajo, María Alcázar‐Fabra, Juan Diego Hernández‐Camacho, Ana Sánchez‐Cuesta, Ana belen Cortes Rodriguez, Manuel Ballesteros‐Simarro, Antonio Arroyo‐Luque, Juan Carlos Rodríguez‐Aguilera, Daniel J.M. Fernández‐Ayala, Gloria Brea‐Calvo, Guillermo López‐Lluch, Carlos Santos‐Ocaña
Abstract
Abstract Coenzyme Q 10 (CoQ 10 ) deficiency is a rare disease characterized by a decreased accumulation of CoQ 10 in cell membranes. Considering that CoQ 10 synthesis and most of its functions are carried out in mitochondria, CoQ 10 deficiency cases are usually considered a mitochondrial disease. A relevant feature of CoQ 10 deficiency is that it is the only mitochondrial disease with a successful therapy available, the CoQ 10 supplementation. Defects in components of the synthesis machinery caused by mutations in COQ genes generate the primary deficiency of CoQ 10 . Mutations in genes that are not directly related to the synthesis machinery cause secondary deficiency. Cases of CoQ 10 deficiency without genetic origin are also considered a secondary deficiency. Both types of deficiency can lead to similar clinical manifestations, but the knowledge about primary deficiency is deeper than secondary. However, secondary deficiency cases may be underestimated since many of their clinical manifestations are shared with other pathologies. This review shows the current state of secondary CoQ 10 deficiency, which could be even more relevant than primary deficiency for clinical activity. The analysis covers the fundamental features of CoQ 10 deficiency, which are necessary to understand the biological and clinical differences between primary and secondary CoQ 10 deficiencies. Further, a more in‐depth analysis of CoQ 10 secondary deficiency was undertaken to consider its origins, introduce a new way of classification, and include aging as a form of secondary deficiency.