D2HGDH (D-2-Hydroxyglutarate Dehydrogenase) is a mitochondrial enzyme involved in the metabolism of D-2-hydroxyglutarate, a cellular byproduct. It helps prevent the harmful accumulation of this compound. Dysfunction of D2HGDH is associated with D-2-hydroxyglutaric aciduria, a disorder linked to symptoms such as developmental delays, epilepsy, and heart conditions.