[Prenatal diagnosis of Sandhoff's disease (GM2-gangliosidosis, type 2)].

The diagnosis of GM2-gangliosidosis type 2 (Sandhoff's disease) was made prenatally (23rd week of pregnancy) by amniocentsis. A sibling with "Tay-Sachs disease" had died shortly before. Severe deficiency of total beta-hexosaminidase was found in amniotic fluid and amnion-cell culture. After interruption of the pregnancy the enzyme defect was also found in the fetal brain tissue and the concentration of ganglioside GM2 was three times normal, confirming the diagnosis.