Seattle Children's Research Institute, Seattle, WA 98101, United States.
J Neurosci Methods. 2009 Oct 30;184(1):136-41. doi: 10.1016/j.jneumeth.2009.07.019. Epub 2009 Jul 23.
Pyridoxine-dependent seizures (PDS) is an autosomal recessive disorder characterized by seizures presenting in neonates or infants up to 3 years of age which respond to pharmacological doses of pyridoxine. Alpha-aminoadipic semialdehyde dehydrogenase (antiquitin) deficiency was identified as an underlying defect in PDS characterized by accumulation of alpha-aminoadipic semialdehyde (alpha-AASA) as a specific marker and recently folinic acid-responsive seizures (FRS) were found to be allelic to PDS as the putative mutations were identified in the antiquitin gene (ALDH7A1). alpha-AASA is known to be in reversible equilibrium with its cyclic Shiff base, delta(1)-piperideine-6-carboxylate (P6C). Pipecolic acid (PA) is another biomarker often elevated but is not specific to PDS. Here, we developed the liquid chromatography-mass spectrometry (LC-MS/MS) method to determine the analytes of alpha-AASA, P6C and PA simultaneously in plasma and validated the assay using samples from confirmed cases. This approach eliminates the extra time and expense of running multiple assays and provides valuable information for the rapid diagnosis and treatment of patients with PDS and FRS which potentially could lead to a better outcome with improved quality of life. The stability study showed that alpha-AASA and P6C were unstable even at -20 degrees C. A careful sample handling with immediate freezing and testing is required for reliable result.
吡哆醇依赖性癫痫（PDS）是一种常染色体隐性遗传疾病，其特征为新生儿或 3 岁以下婴儿出现癫痫发作，对大剂量吡哆醇有反应。α-氨基己二酸半醛脱氢酶（antiquitin）缺乏症被确定为 PDS 的潜在缺陷，其特征是α-氨基己二酸半醛（alpha-AASA）的积累作为特定标志物，最近发现叶酸反应性癫痫（FRS）与 PDS 等位相关，因为在 antiquitin 基因（ALDH7A1）中鉴定出了假定的突变。α-AASA 已知与它的环状 Shiff 碱基 δ(1)-哌啶-6-羧酸（P6C）处于可逆平衡中。吡咯烷酮羧酸（PA）是另一种经常升高但特异性不强的生物标志物。在这里，我们开发了液相色谱-质谱联用（LC-MS/MS）方法，同时在血浆中测定 alpha-AASA、P6C 和 PA 的分析物，并使用确诊病例的样本验证了该测定方法。这种方法消除了运行多个测定方法的额外时间和费用，并为 PDS 和 FRS 患者的快速诊断和治疗提供了有价值的信息，这可能会导致生活质量的提高和更好的结果。稳定性研究表明，即使在-20°C 下，alpha-AASA 和 P6C 也不稳定。需要小心处理样本，立即冷冻并进行测试，以确保结果可靠。
