Raghunath M, Steinmann B, Delozier-Blanchet C, Extermann P, Superti-Furga A
Department of Pediatrics, University of Zürich, Switzerland.
Pediatr Res. 1994 Oct;36(4):441-8. doi: 10.1203/00006450-199410000-00005.
We have developed a method for early prenatal diagnosis of molecular disorders of collagens I and III. The method takes advantage of the fact that isolated chorionic villi contain significant amounts of collagens in their extracellular matrix (stroma) and that they synthesize collagens in vitro. After metabolic labeling of chorion villus biopsies in toto with radioactive amino acids, collagens are extracted and analyzed by SDS-PAGE. Direct staining of the gel shows collagens synthesized in vivo, whereas autoradiofluorography identifies collagens synthesized during incubation in vitro. Unlike collagens synthesized by cultured amniotic fluid cells, collagens extracted from chorionic villi are not overmodified and thus allow better identification of molecular defects. Results are available within 3 to 5 d after biopsy. Using this method, we have correctly excluded Ehlers-Danlos syndrome type IV in two pregnancies, Ehlers-Danlos syndrome type VII in one pregnancy, and lethal osteogenesis imperfecta in four pregnancies. In addition, we correctly predicted a healthy fetus and an embryo affected with lethal osteogenesis imperfecta in consecutive pregnancies from a couple in which the asymptomatic mother was a somatic mosaic for a COL1A1 G-to-A transition (Gly355Asp). Direct collagen analysis of chorion villus biopsies labeled in toto is rapid and reliable and may become the method of choice for the prenatal diagnosis of selected collagen disorders.
我们已经开发出一种用于早期产前诊断I型和III型胶原蛋白分子疾病的方法。该方法利用了以下事实：分离出的绒毛膜绒毛在其细胞外基质（基质）中含有大量胶原蛋白，并且它们在体外能够合成胶原蛋白。在用放射性氨基酸对绒毛膜绒毛活检标本进行整体代谢标记后，提取胶原蛋白并通过SDS-PAGE进行分析。凝胶的直接染色显示体内合成的胶原蛋白，而放射自显影则可识别体外孵育期间合成的胶原蛋白。与培养的羊水细胞合成的胶原蛋白不同，从绒毛膜绒毛中提取的胶原蛋白没有过度修饰，因此能够更好地识别分子缺陷。活检后3至5天即可获得结果。使用这种方法，我们已经在两次妊娠中正确排除了IV型埃勒斯-当洛综合征，在一次妊娠中排除了VII型埃勒斯-当洛综合征，在四次妊娠中排除了致死性成骨不全症。此外，我们正确预测了一对夫妇连续妊娠中的一个健康胎儿和一个受致死性成骨不全症影响的胚胎，该夫妇中无症状的母亲是COL1A1基因G到A转换（Gly355Asp）的体细胞嵌合体。对整体标记的绒毛膜绒毛活检标本进行直接胶原蛋白分析快速且可靠，可能会成为某些胶原蛋白疾病产前诊断的首选方法。
