Defects in GLYCTK are the cause of D-glyceric aciduria (D-GA). D-GA is a rare metabolic disease characterized by chronic metabolic acidosis and a highly variable clinical phenotype. Clinical features range from an encephalopathic presentation with seizures, microcephaly, severe mental retardation and early death, to milder manifestations with only speech delay or even normal development. Belongs to the glycerate kinase type-2 family. 7 isoforms of the human protein are produced by alternative splicing.Guo J.-H., DNA Seq. 17:1-7(2006).Wan D., Proc. Natl. Acad. Sci. U.S.A. 101:15724-15729(2004).Ota T., Nat. Genet. 36:40-45(2004).