In our country the prenatal diagnosis of lysosomal diseases with enzymatic techniques has been conducted since 1988. This paper describes 12 clinical cases of prenatal diagnosis in 11 couples who were known carriers of lysosomal diseases, all with affected and/or deceased children. Mothers underwent amniocentesis between 16-20 weeks of pregnancy, and samples were simultaneously processed with a control of the same gestational age. Amniocytes were cultured during 18 days, after which the enzymatic activities of α-L-iduronidase (for the MPS I case), arylsulphatase B (for MPS VI cases), α-L-fucosidase (for fucosidosis cases), β-galactosidase (for GM-1 gangliosidosis cases), β-glucosidase (for Gaucher cases), hexosaminidase A (for the Tay-Sachs case) and sphyngomyelinase (for the Niemann Pick case) were quantified. All 12 prenatal diagnoses were negative for the corresponding lysosomal disease and all pregnancies ended in a healthy newborn and in children with normal living. We concluded that prenatal enzymatic diagnosis was useful for defining the possible affection of the fetus and contributed to support genetic counseling for lysosomal diseases, although it does not rule out the need for molecular biology in doubtful cases.
