Prenatal diagnosis of lysosomal storage diseases using fetal blood

Lysosomal storage diseases are a rare but significant cause of non-immune h ydrops fetalis (NIHF). In 17 cases of NIHF detected by ultrasound, the acti vity of five lysosomal enzymes was measured in leukocytes or plasma of 1 mi of fetal blood obtained by cordocentesis. By this approach seven lysosomal storage diseases known to present with hydrops fetalis can be diagnosed. I n this series one case of mucopolysaccharidosis VII (hii. Sly) was diagnose d at 20 weeks' gestation. The other samples allowed the establishment of re ference ranges for lysosomal enzymes associated with NIHF in fetal blood. W e conclude that, also in view of the poor prognosis of lysosomal storage di seases presenting with hydrops fetalis, the use of fetal blood for the earl y and fast biochemical diagnosis of these diseases is a valuable supplement in the diagnostic work-up and the management of NIHF. Copyright (C) 1999 J ohn Wiley & Sons, Ltd.