DARS1 and hypomyelinating leukodystrophy 9: Mutations in numerous aminoacyl-tRNA synthetases (ARSs) are also linked to hypomyelination, such as in HBSL (Hypomyelination with Brainstem and Spinal cord involvement and Leg spasticity, DARS related disorder) or HLD9 (Hypomyelinating Leukodystrophy 9, RARS related disorder)42–46.