DARS2 and Leukoencephalopathy: Dars2 encodes the mitochondrial aspartyl-tRNA synthetase (mt-AspRS) and mutations in the Dars2 gene result in leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL), which was first described in 2003 (van der Knaap et al., 2003; Scheper et al., 2007).