2. Amnion cells/Chorionic villi: enzyme measurements of ß-Glucocerebrosidase (Gaucher disease), N-Acetyl-Glukosamin-6-Sulfatsulfatase (MPS IVA), ß-Glucoronidase (MPS VII), Neuraminidase and ß-Galactosidase (Galactosialidosis, GM1 Gangliosidosis and Sialidosis). Ceramidase (Farber disease), Acid lipase (Wolman disease), Sphingomyelinase (NPA). The gene discussed is GBA1; the disease is sialidosis.