GBA1 and Gaucher disease: Gaucher disease is caused by homozygous mutations in GBA1, which are an important risk factor for Parkinson disease59, and mutations in the non-lysosomal GBA2 have been linked to hereditary spastic paraplegia60 and spastic ataxia61.The covalent binding of CBE to GCases may easily lead to full inhibition of total GCase activity if given in high enough dose, as shown in our in vitro assay.