PRENATAL-DIAGNOSIS OF PYRUVATE-CARBOXYLASE DEFICIENCY BY DIRECT MEASUREMENT OF CATALYTIC ACTIVITY ON CHORIONIC VILLI SAMPLES

(P)yruvate carboxylase (PC) deficiency is a rare metabolic disorder in infants and children, most frequently with fatal outcome. Its prenata l diagnosis by radiometric assay in cultured amniocytes has previously been reported. We present and discuss the prenatal diagnosis of PC de ficiency by direct measurement of PC activity in chorionic villi, in t wo subsequent pregnancies in a Family who previously lost a child affe cted by PC deficiency. In the next pregnancy PC was unmeasurably low i n chorionic villi whereas in control samples its activity was between 0.8 and 3.3 nmol min(-1) mg protein(-1). Following elective terminatio n of the pregnancy PC was shown to be totally inactive in post-mortem fetal liver. In the most recent pregnancy of the proband's mother PC w as normally active in the chorionic villi. The product of this pregnan cy was a normal boy, (C) 1998 John Wiley & Sons, Ltd.