Coenzyme Q(10) is frequently reduced in muscle of patients with mitochondrial myopathy

Coenzyme Q(10) (CoQ(10)) deficiency has been associated with an increasing number of clinical phenotypes. Whereas primary CoQ(10) defects are related to mutations in lubiquinone biosynthetic genes, which are now being unraveled, and respond well to CoQ(10) Supplementation. the etiologies, and clinical phenotypes related to secondary deficiencies are largely unknown. The purpose of this multicenter Study was to evaluate the frequency of muscle CoQ(10) deficiency in a cohort of 76 patients presenting with clinically heterogeneous mitochondrial phenotypes which included myopathy among their clinical features. A reliable diagnostic tool based oil HPLC quantification was employed to measure muscle CoQ(10) levels. A significant proportion of these patients (28 over 76) displayed CoQ(10) deficiency that was clearly secondary in mile patients, who harbored a pathogenic mutation of mitochondrial DNA. This study provides a rationale for future therapeutic trials on the effect of CoQ(10) supplementation in patients with mitochondrial diseases presenting with myopathy among clinical features. (C) 2009 Elsevier B.V. All rights reserved.