DARS1 and Leukoencephalopathy: Mutations of DARS1 and its homolog DARS2 have been reported in patients showing hypomyelination in the brainstem, spinal cord and leg spasticity (HBSL), and leukoencephalopathy brain stem and spinal cord involvement and elevated lactate (LBSL), which demonstrates that mutation in tRNA causes a similar disease and shares a common mechanism of neurological pathology [65].