Successful First Trimester Diagnosis in a Pregnancy at Risk for Propionic Acidaemia

Abstract

Propionic acidaemia is an inborn error of amino acid metabolism caused by a deficiency of propionyl-CoA carboxylase (PCC) (EC 6.4.1.3). PCC activity has been demonstrated in several tissues including fibroblasts, amniotic fluid cells and chorionic villi (Sweetman et al., 1986). Prenatal diagnosis of propionic acidaemia can be performed by the determination of the methylcitrate level in amniotic fluid (Naylor et al., 1980), by studies of incorporation of [1-¹⁴C]propionate into protein of amniocytes (Willard et al., 1976) and by direct assay of PCC activity in cultured amniotic fluid cells (Gompertz et al., 1975) or in intact chorionic villi (Chadefaux et al., 1988). We report a successful first trimester diagnosis by direct PCC assay in uncultured chorionic villi in a pregnancy at risk for propionic acidaemia.