AARS1 and Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia: Most cases of ALSP are due to the CSF1R mutations; however, AARS2 mutations were reported in CSF1R-negative ALSP, a single Swedish HDLS family was found to carry an AARS1 mutation, and ALSP without CSF1R, AARS1 or AARS2 mutation was reported [7–9].