Millington David S, Stevens Robert D
DUMC Biochemical Genetics Laboratory, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA.
Methods Mol Biol. 2011;708:55-72. doi: 10.1007/978-1-61737-985-7_3.
The acylcarnitine profile is a diagnostic test for inherited disorders of fatty acid and branched-chain amino acid catabolism. Patients with this type of metabolic disorder accumulate disease-specific acylcarnitines that correlate with the acyl coenzyme A compounds in the affected mitochondrial metabolic pathways. For example, propionylcarnitine accumulates in patients with both propionic and methylmalonic acidemias. The test identifies and quantifies the species of acylcarnitines in the whole blood or blood plasma of patients at risk for or suspected of having such a disorder. The acylcarnitines are analyzed using electrospray ionization-tandem mass spectrometry. The instrument is used in the precursor ion scan mode to record the molecular species giving rise to fragment ions at m/z 99, derived specifically from the methylated acylcarnitines within the specimen. Quantification is based on the principle of stable isotope dilution, whereby concentrations are derived from the response ratio of each acylcarnitine species to that of a deuterium-labeled acylcarnitine standard. Interpretation of the acylcarnitine profile requires recognition of abnormal concentrations of specific analytes or patterns of analytes and knowledge of their metabolic origin.
酰基肉碱谱是一种用于诊断脂肪酸和支链氨基酸分解代谢遗传性疾病的检测方法。患有此类代谢紊乱的患者会积累与受影响的线粒体代谢途径中的酰基辅酶A化合物相关的疾病特异性酰基肉碱。例如，丙酰肉碱在丙酸血症和甲基丙二酸血症患者中都会积累。该检测可识别和定量处于此类疾病风险或疑似患有此类疾病的患者全血或血浆中的酰基肉碱种类。使用电喷雾电离串联质谱法分析酰基肉碱。该仪器以前体离子扫描模式运行，记录在m/z 99处产生碎片离子的分子种类，这些碎片离子专门源自样本中的甲基化酰基肉碱。定量基于稳定同位素稀释原理，即浓度由每种酰基肉碱种类与氘标记酰基肉碱标准品的响应比得出。酰基肉碱谱的解读需要识别特定分析物的异常浓度或分析物模式以及了解它们的代谢来源。
