This seminal observation was followed by several studies showing CSF1R mutations in both familial and sporadic cases of HDLS [27,36,40,41,42,49,51,58,68,69,70,71,72,73], POLD [29], and ALSP [36,38,41,44,46,74,75,76,77,78]. This evidence concerns the gene CSF1R and Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia.