Kubaski Francyne, Burlina Alberto, Polo Giulia, Pereira Danilo, Herbst Zackary M, Silva Camilo, Trapp Franciele B, Michelin-Tirelli Kristiane, Lopes Franciele F, Burin Maira G, Brusius-Facchin Ana Carolina, Netto Alice B O, Faqueti Larissa, Iop Gabrielle D, Poletto Edina, Giugliani Roberto
BioDiscovery Laboratory, Hospital de Clinicas de Porto Alegre, Porto Alegre 90035-903, Brazil.
PPGBM, UFRGS, Porto Alegre 91501-970, Brazil.
Int J Neonatal Screen. 2022 Jun 28;8(3):39. doi: 10.3390/ijns8030039.
Niemann-Pick disease type C (NPC) is a lysosomal disorder caused by impaired cholesterol metabolism. Levels of lysosphingomyelin 509 (LysoSM509) have been shown elevated in dried blood spots (DBS) of NPC and acid sphingomyelinase deficiency patients. In this study, we report our experience using a two-tier approach (1st tier is the quantification of lysoSM509 by ultra-performance liquid chromatography tandem mass spectrometry followed by the 2nd tier with next-generation sequencing of the and genes). DBS samples from 450 suspected patients were received by the NPC Brazil network. Of these, 33 samples had elevated levels of lysoSM509, and in 25 of them, variants classified as pathogenic, likely pathogenic, or of unknown significance were identified in the or genes by next-generation sequencing. The quantification of lysoSM509 in DBS as a first-tier test for the diagnosis of NPC followed by molecular analysis of the and genes almost doubled the detection rate when compared to the performance of chitotriosidase activity as a first-tier biomarker, and it could likely be increased with the addition of a third tier with MLPA of the two genes involved. This strategy seems suitable for the neonatal screening (NBS) of NPC if this disease is eventually adopted by NBS programs.
尼曼-匹克C型病（NPC）是一种由胆固醇代谢受损引起的溶酶体疾病。已显示NPC患者和酸性鞘磷脂酶缺乏症患者的干血斑（DBS）中溶血鞘磷脂509（LysoSM509）水平升高。在本研究中，我们报告了使用两级方法的经验（第一层是通过超高效液相色谱串联质谱法定量LysoSM509，接着第二层是对 和 基因进行下一代测序）。NPC巴西网络接收了来自450名疑似患者的DBS样本。其中，33个样本的LysoSM509水平升高，通过下一代测序在其中25个样本的 或 基因中鉴定出分类为致病、可能致病或意义不明的变异。与将壳三糖苷酶活性作为第一层生物标志物的检测性能相比，将DBS中LysoSM509的定量作为NPC诊断的第一层检测，随后对 和 基因进行分子分析，检测率几乎提高了一倍，并且通过增加涉及这两个基因的MLPA作为第三层检测，检测率可能会进一步提高。如果最终NBS计划采用这种疾病，这种策略似乎适用于NPC的新生儿筛查（NBS）。
