Definition:

The alpha-ketoglutarate dehydrogenase complex (KGDHC) deficiency is a rare autosomal recessive disorder, most often presenting with severe encephalopathy and hyperlactatemia with neonatal onset. KGDHC is mitochondrial enzyme complex, and functions in the TCA cycle. This enzymatic complex is made up of three subunits, encoded by OGDH, DLST, and DLD, respectively. The E3 subunit, encoded by DLD, is common to two other enzymatic complexes, namely pyruvate dehydrogenase complex and branched-chain ketoacid dehydrogenase complex. It has also been reported that reductions in the KGDHC occur in a number of neurodegenerative disorders including Alzheimer's disease.