Prenatal diagnosis of organic acidemia by measuring index compounds in dried amniotic fluid on filter paper using GC/MS

用GC/MS测定滤纸上干燥无细胞羊水（AF）指标化合物对丙酸血症或多种羧化酶缺乏症产前诊断的研究即使是一个偏远地区医院的医生，如果他使用这个系统，也可以给我们发送一个样本。测定系统的建立：1)如何知道AF在干燥滤纸上的进样量是最关键的一点，建立了如下计算方法。它只是在已知重量的滤纸上饱和AF，并在室温下现场干燥。根据纸张的重量可以计算出AF的吸收量。2)滤纸提取确认及重现性：将已知数量的指标化合物加入AF中，吸到滤纸上干燥。它是用滤纸中的蒸馏水提取的。采用前人AF报道的方法制备提取液进行GC/MS分析，并将测定数据与原AF的测定数据进行比较。控制值：用滤纸吸附对照羊水，测定样品的控制值。我们还分析了丙酸血症“高危”孕妇羊水滤纸，并对每个病例进行了明确的诊断。这种方法是半定量分析，但很明显，这种方法是适用于产前诊断。

Study of prenatal diagnosis of propionic acidemia or multiple carboxylase deficiency by measuring index compounds in dried cell-free amniotic fluid (AF) on filter paper using GC/MS. Even a doctor of a hospital of a remote region can send a sample to us if he uses this system.1.Establish of assay system:1) It was a most key point how to know the sampling volume of AF on a dried filter paper: It was established a calculating method as below. It was only saturated a filter paper known weight with AF and dried up under room temperature on site. It could be calculated the absorbed volume of AF from the weight of paper.2) Confirmation of extraction from filter paper and reproducibility: Known quantity of index compounds was added to AF, and it was absorbed to a filter paper and dried. It was extracted with distilled water from the filter paper. The extractive was prepared for GC/MS analysis by the method of previous report of AF. The measurement data were compared with the data of original AF.2. Control Values:We measured the sample which let a filter paper absorb control amniotic fluid and found control value. We also analyzed the filter paper of the amniotic fluids from pregnancies "at risk" for propionic academia, and could make a clear-cut diagnosis to each cases.This method is a semiquantitative analysis, but it became clear that this method is applicable for prenatal diagnosis.