First Trimester Prenatal Diagnosis of Glycogen Storage Disease Type III

Abstract

Glycogen storage disease (GSD) type III (McKusick 23240) is an autosomal recessive disorder due to a deficiency of glycogen debranching enzyme (Illingworth et al., 1956). This enzyme presents a transferase activity: oligo a-1,4-glucan-a-1,4 glucan-4-glycosyltransferase (EC 2.4.1.25) and a hydrolytic activity: amylo-1,6-glucosidase (EC 3.2.1.33); both activities have been located on the same macromolecule. Debranching enzyme deficiencies have been reported in muscle, liver, leukocytes, erythrocytes and fibroblasts. Generally, the course of the disease seems rather mild, in spite of some difficulties in long-term outcome (De Parscau et al., 1988); but, in some cases, an unusually severe course in a previous child leads the parents to request a prenatal diagnosis for a further pregnancy. We have previously reported the possibility of prenatal diagnosis of GSD type III using cultured amniotic fluid (AF) cells (Maire and Mathieu, 1986) and the feasibility of the diagnosis using chorionic villi (CV) has been suggested by Van Diggelen et al. (1985). We report here the first trimester prenatal diagnosis of an affected case.