USE OF AMNIOTIC-FLUID AIMING ACIDS IN PRENATAL TESTING FOR ARGININOSUCCINIC ACIDURIA AND CITRULLINEMIA

Prenatal testing of 12 pregnancies at risk for argininosuccinic acidur ia due to argininosuccinate lyase (ASAL) deficiency and three pregnanc ies at risk for citrullinaemia due to argininosuccinate synthatase (AS AS) deficiency was performed by metabolite detection in amniotic fluid and measurement of enzyme activity in uncultured and cultured chorion ic tissue and in cultured amniocytes. From our data and those of previ ous studies, amniotic fluid argininosuccinate measurement alone is cle arly a reliable and rapid diagnostic test for both severe and mild ASA L deficiency if maternal ASAL deficiency can be excluded. For prenatal diagnosis of ASAS deficiency, however, both measurement of the amniot ic fluid citrulline level and enzyme assay should be employed.