Late onset Krabbe disease due to the new GALC p.Ala543Pro mutation, with intriguingly high residual GALC activity in vitro.

Background: Krabbe disease (KD) is an inherited leukodystrophy due to a defect in the GALC gene which encodes the lysosomal galactosylceramide β-galactosidase (GALC). About two thirds of patients show the early onset form of KD dominated by cerebral demyelination leading to death in early infancy. Late onset forms include a spectrum of late infantile, juvenile and adult clinical courses. The deficiency of GALC leads to a galactosylceramide lipidosis in which lysosomal storage phenomena are seen almost only at the ultrastructural level.