Enables (R)-2-hydroxyglutarate dehydrogenase activity. Involved in several processes, including response to cobalt ion; response to manganese ion; and response to zinc ion. Located in mitochondrion. Human ortholog(s) of this gene implicated in D-2-hydroxyglutaric aciduria 1. Orthologous to human D2HGDH (D-2-hydroxyglutarate dehydrogenase). [provided by Alliance of Genome Resources, Apr 2022]