α-Aminoadipic and α-Ketoadipic Aciduria: Detection of a New Case by a Screening Program using Two-dimensional Thin Layer Chromatography of Amino Acids

α-Aminoadipic acid and α-ketoadipic acid are intermediates of lysine catabolism; they are synthetized mainly via the saccharopine pathway, although the pipecolic acid pathway may be significant in some tissues, such as the central nervous system. α-Ketoadipic acid may be produced also via tryptophan catabolism. Since 1974, 10 patients with α-aminoadipic aciduria (McKusick 20475) have been described but seven of them (Przyrembel et al., 1975; Wilson et al., 1975; Gray et al., 1979; Fischer and Brown, 1980; Duran et al., 1984) were reported to also present α-ketoadipic aciduria (McKusick 24513), suggesting that the enzymatic defect might be located either at the level of α-aminoadipate aminotransferase (α-aminoadipic aciduria only) or at the level of α-ketoadipate dehydrogenase (α-amino- and α-ketoadipic aciduria). In one case (Przyrembel et al., 1975), Wendel et al. (1975) showed that conversion of 14C-labelled α-ketoadipate to 14CO2 was decreased, although glutaryl-CoA dehydrogenase activity was normal.