[Prenatal diagnosis of Gaucher disease]

Gaucher disease (GD, OMIM #230800, 230900, 231000) is a lysosomal surcharge disorder caused by a deficiency in glucocerebrosidase, a lysosomal enzyme also referred to as acid beta-glucosidase or, in rare cases, by a deficiency in the activator protein saposin C. Partial deficiency of acid beta-glucosidase is associated with the presence of glucosylceramide, also known as glucocerebroside (Gb1), deposits in the reticuloendothelial cells of the liver, spleen and bone marrow, in non-neuronopathic type 1, GD. Profound deficiency of acid beta-glucosidase caused by disabling mutations is additionally associated with neurological manifestations in the less common type 2 and type 3 Gaucher diseases. Type 2 GD culminates in early death as a result of devastating neurological disease. Congenital ichtyosis with a collodion baby phenotype is also part of the spectrum of clinical presentations of type 2 GD. Recombinant glucocerebrosidase (imiglucerase) is an effective mean of treating type 1 GD and should be initiated early on in life. Although imiglucerase has recently been approved for the treatment of type 3 GD, enzyme replacement therapy cannot reverse the neurological manifestations in type 2 or type 3 GD. Following genetic counseling and informed consent, direct enzymatic assay of acid beta-glucosidase and molecular testing of the GBA mutations on chorionic villi samples (CVS) can be offered to families in which type 2 or type 3 GD has been diagnosed. Improvement in substrate deprivation therapy or gene therapy may provide a cure for patients with these disorders in the future.