Many of these are associated with neurodegenerative diseases, such as mitochondrial aspartyl-tRNA synthetase (DARS2) and mitochondrial glutamyl-tRNA synthetase (EARS2) with leukoencephalopathy, mitochondrial arginyl-tRNA synthetase (RARS2) with pontocerebellar hypoplasia, mitochondrial phenylalanyl-tRNA synthetase (FARS2) with mitochondrial encephalopathy and MARS2 with autosomal recessive spastic ataxia with leukoencephalopathy (ARSAL) in humans [3]. The gene discussed is RARS2; the disease is Leukoencephalopathy.