Annual Report 2006–07

研究 Research 57 盧 煜明教授（化學病理學系）領導其研究隊 伍，發展出一個新的唐氏綜合症無創產前 檢測法。 這方法是透過分析孕婦血漿內由胎盤釋放出來其 中一個名為PLAC4的基因，若胎兒是正常的話， 胎兒從父親和母親所遺傳到的PLAC4 基因的比例 是一比一，若胎兒有唐氏綜合症，該比例便會變 成一比二或二比一。 盧教授及其研究隊伍利用質譜儀來精確地量度這 比例，這方法的靈敏度和特異性甚高，分別為百 分之九十和百分之九十六點五。這技術於二零零 七年二月號的《自然醫學》發表。 The outstanding research project is led by Prof. Lo Yuk-ming Dennis (Department of Chemical Pathology). The test is done by detecting the RNA molecules released by the placenta of a foetus. In particular, RNA molecules from a gene called placenta-specific 4 (PLAC4) are detected. In a normal foetus, the PLAC4 gene ratio would be 1:1 while in a foetus suffering from Down Syndrome, the ratio would be deviated to 1:2 or 2:1. Prof. Lo and his team measure the ratio in high precision with a mass spectrometer, a sensitive instrument which measures molecular masses of nucleic acids. In a series of cases, this test has achieved a sensitivity of 90% and a specificity of 96.5%. This work has been published in the February 2007 issue of Nature Medicine . 傑出研究計劃 Outstanding Research Project 醫學院 Faculty of Medicine 盧煜明教授小組的成員徐寶賢博士 在質譜儀前工作，量度基因比例 Dr. Nancy Tsui, a member of Prof. Lo's team, working in front of the mass spectrometer