GALC and Krabbe disease: Krabbe's disease (KD) is a lysosomal sphingolipidosis caused by mutations in the galactosylceramidase gene (GALC) (Suzuki and Suzuki, 1971) leading to accumulation of the neurotoxic lipid galactosylsphingosine (or psychosine) (Svennerholm et al., 1980; Igisu and Suzuki, 1984).