GALC and Krabbe disease: Globoid cell leukodystrophy or Krabbe disease (KD) (OMIM 245200) is an inherited demyelinating disorder caused by a deficiency of galactosylceramidase (GALC; EC 3.2.1.46), which leads to the accumulation of its substrates galactosylceramide (GalCer) and galactosylsphingosine (also known as psychosine) in myelin-producing cells (Wenger et al., 2019).