Zhang Haoyue, Young Sarah P, Millington David S
Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA.
Curr Protoc Hum Genet. 2013;Chapter 17:Unit 17.12. doi: 10.1002/0471142905.hg1712s76.
Mucopolysaccharidoses (MPSs) are complex lysosomal storage disorders that result in the accumulation of glycosaminoglycans (GAGs) in urine, blood, and tissues. Lysosomal enzymes responsible for GAG degradation are defective in MPSs. GAGs including chondroitin sulfate (CS), dermatan sulfate (DS), heparan sulfate (HS), and keratan sulfate (KS) are disease-specific biomarkers for MPSs. This unit describes a stable isotope dilution-tandem mass spectrometric method for quantifying CS, DS, and HS in urine samples. The GAGs are methanolyzed to uronic or iduronic acid-N-acetylhexosamine or iduronic acid-N-sulfo-glucosamine dimers and mixed with internal standards derived from deuteriomethanolysis of GAG standards. Specific dimers derived from HS, DS, and CS are separated by ultra-performance liquid chromatography (UPLC) and analyzed by electrospray ionization tandem mass spectrometry (MS/MS) using selected reaction monitoring for each targeted GAG product and its corresponding internal standard. This new GAG assay is useful for identifying patients with MPS types I, II, III, VI, and VII.
黏多糖贮积症（MPSs）是复杂的溶酶体贮积病，会导致糖胺聚糖（GAGs）在尿液、血液和组织中蓄积。在MPSs中，负责GAG降解的溶酶体酶存在缺陷。包括硫酸软骨素（CS）、硫酸皮肤素（DS）、硫酸乙酰肝素（HS）和硫酸角质素（KS）在内的GAGs是MPSs的疾病特异性生物标志物。本单元介绍了一种用于定量尿液样本中CS、DS和HS的稳定同位素稀释串联质谱法。将GAGs进行甲醇解，生成糖醛酸或艾杜糖醛酸 - N - 乙酰己糖胺或艾杜糖醛酸 - N - 磺基 - 葡糖胺二聚体，并与由GAG标准品的氘代甲醇解衍生而来的内标混合。通过超高效液相色谱（UPLC）分离HS、DS和CS衍生的特定二聚体，并使用针对每种目标GAG产物及其相应内标的选择反应监测，通过电喷雾电离串联质谱（MS/MS）进行分析。这种新的GAG检测方法对于识别I型、II型、III型、VI型和VII型MPS患者很有用。
