ASAH1 and Krabbe disease: The first is a syntheticpathway, where ceramide galactosyltransferase catalyzes the additionof a β-d-galactosyl group to sphingosine., The second pathway involves the degradation of galactosylceramide(GalCer) by acid ceramidase, which hydrolyzes ceramides into sphingosineand fatty acids. It is also reportedthat GALC deficiency results in the accumulation of GalSph as a primarymetabolite and, to a lesser extent, GalCer. The precise mechanisms underlying sphingolipid-induced toxicityin GLD remain poorly understood.