EARS2 and spastic ataxia: Similarly, several genetic mutations in EARS2 (mitochondrial glutamyl-tRNA synthetase), MARS2 (mitochondrial methionyl-tRNA synthetase) and FARS2 (mitochondrial phenylalanyl-tRNA synthetase) cause leukoencephalopathy with thalamus and brainstem involvement and high lactate (LTBL) (Steenweg et al, 2012), spastic ataxia with leukoencephalopathy (Bayat et al, 2012) and Alpers encephalopathy (Elo et al, 2012), respectively.