Rapid differential diagnosis of carboxylase deficiencies and evaluation for biotin-responsiveness in a single blood sample.
We have developed a method for rapid differential diagnosis of isolated or multiple deficiencies of the 3 mitochondrial biotin-dependent carboxylases: propionyl-CoA (PCC), 3-methylcrotonyl-CoA (MCC) and pyruvate carboxylase (PC), and for simultaneous evaluation of biotin-responsiveness using a single blood sample. Lymphocytes were isolated from heparinized blood and preincubated without and with 10(-5) mol/l biotin in medium before determination of PCC, MCC and PC activities. Plasma was used for estimation of biotin concentration and biotinidase activity. A definitive diagnosis could be made in 7 of 9 patients studied up to now: 4 patients suffered from biotin-nonresponsive isolated PCC-deficiency, and 3 patients from biotin-responsive multiple carboxylase deficiency caused by deficient biotinidase activity. In two patients, a carboxylase deficiency was excluded. These results were confirmed in studies using fibroblasts. In addition, a simple method for detection of deficiency in holocarboxylase synthesis is described.
D000214:Acyl Coenzyme A / Q000097:blood / Q000172:deficiency; D000328:Adult; D000581:Amidohydrolases / Q000097:blood; D001710:Biotin; D043523:Biotinidase; D019735:Carbon-Carbon Ligases; D019731:Carbon-Nitrogen Ligases; D002478:Cells, Cultured; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D007223:Infant; D008025:Ligases / Q000037:antagonists & inhibitors / Q000097:blood / Q000172:deficiency*; D008214:Lymphocytes / Q000201:enzymology; D011766:Pyruvate Carboxylase / Q000097:blood; D015324:Pyruvate Carboxylase Deficiency Disease
D000214:Acyl Coenzyme A; C009061:propionyl-coenzyme A; D001710:Biotin; D000581:Amidohydrolases; D043523:Biotinidase; D008025:Ligases; D019731:Carbon-Nitrogen Ligases; C023312:holocarboxylase synthetases; D019735:Carbon-Carbon Ligases; D011766:Pyruvate Carboxylase; C021573:methylcrotonoyl-CoA carboxylase