Brivet M, Garcia-Cazorla A, Lyonnet S, Dumez Y, Nassogne M C, Slama A, Boutron A, Touati G, Legrand A, Saudubray J M
Laboratory of Biochemistry, IFR and AP-HP Hopital de Bicêtre, 78, rue du général Leclerc, Le Kremlin-Bicêtre Cedex 94275, France.
Mol Genet Metab. 2003 Mar;78(3):186-92. doi: 10.1016/s1096-7192(03)00016-7.
The patient was the first child of healthy consanguineous parents. She presented at birth with hypotonia, mild facial dysmorphism, periventricular cysts, marked metabolic acidosis, hyperlactacidemia with normal lactate/pyruvate molar ratios, normoglycemia, and normal ammonia. Hyperlactacidemia was severe (5-14 mmol/l) and not corrected with bicarbonate, thiamine (10 mg/d), 2-chloropropionate (100 mg/kg/d) and a ketogenic diet. Pyruvate dehydrogenase (PDHC) activity was normal in lymphocytes and fibroblasts. Functional assays were performed in digitonin-permeabilized fibroblasts to measure oxidation rates from radiolabeled pyruvate and malate. The production of [14C]acetylcarnitine or [14C]citric cycle intermediates derived from [2-14C]pyruvate as well as the release of 14CO(2) from [1-14C]pyruvate was severely impaired, whereas decarboxylation of [U-14C]malate was normal. With increasing concentrations of [1-14C]pyruvate, the patient's fibroblasts behave like control fibroblasts incubated in the presence of alpha-cyano-4-hydroxycinnamate, a specific inhibitor of mitochondrial pyruvate uptake: a progressive increase in 14CO(2) production was observed, likely due to passive diffusion of [1-14C]pyruvate through the mitochondrial membranes. Our results are consistent with a defect of mitochondrial pyruvate transport in the patient. Mutational analysis was precluded as the cDNA sequence of the pyruvate carrier has not been identified as yet in any organism. An affected fetus was recognized in a subsequent dichorionic twin pregnancy using the coupled assay measuring [2-14C]pyruvate oxidation rates on digitonin-permeabilized trophoblasts. After selective feticide, the pregnancy was uncomplicated with delivery at 37w of a healthy female, who is currently 2-month old.
该患者是健康近亲父母的第一个孩子。她出生时表现为肌张力减退、轻度面部畸形、脑室周围囊肿、明显的代谢性酸中毒、乳酸/丙酮酸摩尔比正常的高乳酸血症、血糖正常和血氨正常。高乳酸血症严重（5 - 14 mmol/l），用碳酸氢盐、硫胺素（10 mg/d）、2 - 氯丙酸（100 mg/kg/d）和生酮饮食无法纠正。淋巴细胞和成纤维细胞中的丙酮酸脱氢酶（PDHC）活性正常。在洋地黄皂苷通透的成纤维细胞中进行功能测定，以测量放射性标记的丙酮酸和苹果酸的氧化速率。源自[2 - 14C]丙酮酸的[14C]乙酰肉碱或[14C]柠檬酸循环中间体的产生以及[1 - 14C]丙酮酸中14CO(2)的释放严重受损，而[U - 14C]苹果酸的脱羧正常。随着[1 - 14C]丙酮酸浓度的增加，患者的成纤维细胞表现得像在α - 氰基 - 4 - 羟基肉桂酸（一种线粒体丙酮酸摄取的特异性抑制剂）存在下培养的对照成纤维细胞：观察到14CO(2)产生逐渐增加，这可能是由于[1 - 14C]丙酮酸通过线粒体膜的被动扩散。我们的结果与该患者线粒体丙酮酸转运缺陷一致。由于丙酮酸载体的cDNA序列尚未在任何生物体中确定，因此无法进行突变分析。在随后的双绒毛膜双胎妊娠中，通过在洋地黄皂苷通透的滋养层细胞上测量[2 - 14C]丙酮酸氧化速率的偶联测定法识别出一个受影响的胎儿。在选择性减胎术后，妊娠过程顺利，在37周时分娩出一名健康女婴，目前2个月大。
