Mitochondrial dysfunction accounts for a large group of inherited metabolic disorders most of which are due to a dysfunctional mitochondrial respiratory chain (MRC) and, consequently, deficient energy production. MRC function depends on the coordinated expression of both nuclear (nDNA) and mitochondrial (mtDNA) genomes. Thus, mitochondrial diseases can be caused by genetic defects in either the mitochondrial or...
Succinyl-coenzyme A synthase is a mitochondrial matrix enzyme that catalyzes the reversible synthesis of succinate and adenosine triphosphate (ATP) from succinyl-coenzyme A and adenosine diphosphate (ADP) in the tricarboxylic acid cycle. This enzyme is made up of α and β subunits encoded by SUCLG1 and SUCLA2, respectively. We present a child with severe muscular hypotonia, dystonia, failure to thrive, sensorine...
Introduction: Twinkle, the mitochondrial helicase encoded by C10orf2, serves a key function in mtDNA replication and its mutations associated with a broad spectrum of clinical conditions characterized by qualitative or quantitative defects of mtDNA, including infantile-onset spinocerebellar ataxia (IOSCA), progressive external ophthalmoplegia, and the hepatocerebral mtDNA depletion syndrome (MDS). The signs in ...
Complex III of the mitochondrial respiratory chain (CIII) catalyzes transfer of electrons from reduced coenzyme Q to cytochrome c. Low biochemical activity of CIII is not a frequent etiology in disorders of oxidative metabolism and is genetically heterogeneous. Recently, mutations in the human tetratricopeptide 19 gene (TTC19) have been involved in the etiology of CIII deficiency through impaired assembly of th...