Metabolic determinants of ataxia have conspicuously expanded in the last decade, particularly in the field of mitochondrial encephalopathies. Moreover, there are numerous advances in understanding the pathogenetic mechanisms of other metabolic conditions that are already known before, especially for lysosomal disorders, for Niemann-Pick type C, for some organic acidurias, and for congenital disorders of glycosilation. This chapter explains mitochondrial encephalopathies because they are a frequent and rapidly expanding cause of metabolic derangement causing ataxia. The term mitochondrial disorders is applied to the clinical syndromes associated with abnormalities of the common final pathway of the mitochondrial energy metabolism. From a genetic standpoint, the respiratory chain is unique, since it is formed through the complementation of two distinct genetic systems, the nuclear and the mitochondrial genomes. Nuclear genes provide most of the subunits of the respiratory complexes, the factors that control their intra mitochondrial transport, assembly, and turnover, as well as the enzymes for the synthesis of prosthetic groups.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)