{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T14:19:25Z","timestamp":1793283565797,"version":"4.5.0"},"reference-count":15,"publisher":"Oxford University Press (OUP)","issue":"12","license":[{"start":{"date-parts":[[2006,12,1]],"date-time":"2006-12-01T00:00:00Z","timestamp":1164931200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2006,12,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>Background: We recently demonstrated that the promoter of the RASSF1A gene is hypermethylated in the placenta and hypomethylated in maternal blood cells. This methylation pattern allows the use of methylation-sensitive restriction enzyme digestion for detecting the placental-derived hypermethylated RASSF1A sequences in maternal plasma.<\/jats:p>\n               <jats:p>Methods: We performed real-time PCR after methylation-sensitive restriction enzyme digestion to detect placental-derived RASSF1A sequences in the plasma of 28 1st-trimester and 43 3rd-trimester pregnant women. We used maternal plasma to perform prenatal fetal rhesus D (RhD) blood group typing for 54 early-gestation RhD-negative women, with hypermethylated RASSF1A as the positive control for fetal DNA detection.<\/jats:p>\n               <jats:p>Results: Hypermethylated RASSF1A sequences were detectable in the plasma of all 71 pregnant women. The genotype of plasma RASSF1A after enzyme digestion was identical to the fetal genotype in each case, thus confirming its fetal origin. Nineteen of the 54 pregnant women undergoing prenatal fetal RhD genotyping showed undetectable RHD sequences in their plasma DNA samples. The fetal DNA control, RASSF1A, was not detectable in 4 of the 19 women. Subsequent chorionic villus sample analysis revealed that 2 of these 4 women with negative RHD and RASSF1A signals were in fact carrying RhD-positive fetuses.<\/jats:p>\n               <jats:p>Conclusions: Hypermethylated RASSF1A is a universal marker for fetal DNA and is readily detectable in maternal plasma. When applied to prenatal RhD genotyping, this marker allows the detection of false-negative results caused by low fetal DNA concentrations in maternal plasma. This new marker can also be applied to many other prenatal diagnostic and monitoring scenarios.<\/jats:p>","DOI":"10.1373\/clinchem.2006.074997","type":"journal-article","created":{"date-parts":[[2006,10,27]],"date-time":"2006-10-27T00:54:11Z","timestamp":1161910451000},"page":"2211-2218","source":"Crossref","is-referenced-by-count":301,"title":["Hypermethylated RASSF1A in Maternal Plasma: A Universal Fetal DNA Marker that Improves the Reliability of Noninvasive Prenatal Diagnosis"],"prefix":"10.1093","volume":"52","author":[{"given":"KC Allen","family":"Chan","sequence":"first","affiliation":[{"name":"Department of Chemical Pathology,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chunming","family":"Ding","sequence":"first","affiliation":[{"name":"Centre for Emerging Infectious Diseases,"},{"name":"Department of Chemical Pathology,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ageliki","family":"Gerovassili","sequence":"first","affiliation":[{"name":"Harris Birthright Research Centre for Fetal Medicine, King\u2019s College Hospital, London, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sze W","family":"Yeung","sequence":"first","affiliation":[{"name":"Department of Chemical Pathology,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rossa WK","family":"Chiu","sequence":"first","affiliation":[{"name":"Department of Chemical Pathology,"},{"name":"Department of Chemical Pathology,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tse N","family":"Leung","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynaecology, and Li Ka Shing Institute of Health Sciences, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tze K","family":"Lau","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynaecology, and Li Ka Shing Institute of Health Sciences, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stephen SC","family":"Chim","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynaecology, and Li Ka Shing Institute of Health Sciences, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Grace TY","family":"Chung","sequence":"first","affiliation":[{"name":"Department of Chemical Pathology,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kypros H","family":"Nicolaides","sequence":"first","affiliation":[{"name":"Harris Birthright Research Centre for Fetal Medicine, King\u2019s College Hospital, London, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"YM Dennis","family":"Lo","sequence":"first","affiliation":[{"name":"Department of Chemical Pathology,"},{"name":"Department of Chemical Pathology,"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2006,12,1]]},"reference":[{"key":"2020022801315721100_R1","doi-asserted-by":"crossref","unstructured":"Costa JM, Benachi A, Gautier E. New strategy for prenatal diagnosis of X-linked disorders. N Engl J Med2002;346:1502.","DOI":"10.1056\/NEJM200205093461918"},{"key":"2020022801315721100_R2","doi-asserted-by":"crossref","unstructured":"Lo YMD, Hjelm NM, Fidler C, Sargent IL, Murphy MF, Chamberlain PF, et al. Prenatal diagnosis of fetal RhD status by molecular analysis of maternal plasma. N Engl J Med1998;339:1734-1738.","DOI":"10.1056\/NEJM199812103392402"},{"key":"2020022801315721100_R3","doi-asserted-by":"crossref","unstructured":"Chiu RWK, Lau TK, Leung TN, Chow KC, Chui DH, Lo YMD. Prenatal exclusion of \u03b2 thalassaemia major by examination of maternal plasma. Lancet2002;360:998-1000.","DOI":"10.1016\/S0140-6736(02)11086-5"},{"key":"2020022801315721100_R4","doi-asserted-by":"crossref","unstructured":"Bianchi DW, Avent ND, Costa JM, van der Schoot CE. Noninvasive prenatal diagnosis of fetal rhesus D: ready for Prime(r) Time. Obstet Gynecol2005;106:841-844.","DOI":"10.1097\/01.AOG.0000179477.59385.93"},{"key":"2020022801315721100_R5","doi-asserted-by":"crossref","unstructured":"Lo YMD, Leung TN, Tein MS, Sargent IL, Zhang J, Lau TK, et al. Quantitative abnormalities of fetal DNA in maternal serum in preeclampsia. Clin Chem1999;45:184-188.","DOI":"10.1093\/clinchem\/45.2.184"},{"key":"2020022801315721100_R6","doi-asserted-by":"crossref","unstructured":"Leung TN, Zhang J, Lau TK, Chan LYS, Lo YMD. Increased maternal plasma fetal DNA concentrations in women who eventually develop preeclampsia. Clin Chem2001;47:137-139.","DOI":"10.1093\/clinchem\/47.1.137"},{"key":"2020022801315721100_R7","doi-asserted-by":"crossref","unstructured":"Levine RJ, Qian C, Leshane ES, Yu KF, England LJ, Schisterman EF, et al. Two-stage elevation of cell-free fetal DNA in maternal sera before onset of preeclampsia. Am J Obstet Gynecol2004;190:707-713.","DOI":"10.1016\/j.ajog.2003.12.019"},{"key":"2020022801315721100_R8","doi-asserted-by":"crossref","unstructured":"Zhong XY, Burk MR, Troeger C, Jackson LR, Holzgreve W, Hahn S. Fetal DNA in maternal plasma is elevated in pregnancies with aneuploid fetuses. Prenat Diagn2000;20:795-798.","DOI":"10.1002\/1097-0223(200010)20:10<795::AID-PD897>3.0.CO;2-P"},{"key":"2020022801315721100_R9","doi-asserted-by":"crossref","unstructured":"Lo YMD, Lau TK, Zhang J, Leung TN, Chang AM, Hjelm NM, et al. Increased fetal DNA concentrations in the plasma of pregnant women carrying fetuses with trisomy 21. Clin Chem1999;45:1747-1751.","DOI":"10.1093\/clinchem\/45.10.1747"},{"key":"2020022801315721100_R10","unstructured":"van der Schoot CE, Rijnders RJ, Bossers B, de Haas M, Christiaens GC, Dee R. Real-time PCR of bi-allelic insertion\/deletion polymorphisms can serve as a reliable positive control for cell-free fetal DNA in non-invasive prenatal genotyping [Abstract]. Blood2003;102:93a."},{"key":"2020022801315721100_R11","doi-asserted-by":"crossref","unstructured":"Chim SSC, Tong YK, Chiu RWK, Lau TK, Leung TN, Chan LY, et al. Detection of the placental epigenetic signature of the maspin gene in maternal plasma. Proc Natl Acad Sci U S A2005;102:14753-14758.","DOI":"10.1073\/pnas.0503335102"},{"key":"2020022801315721100_R12","doi-asserted-by":"crossref","unstructured":"Grunau C, Clark SJ, Rosenthal A. Bisulfite genomic sequencing: systematic investigation of critical experimental parameters. Nucleic Acids Res2001;29:E65-E65.","DOI":"10.1093\/nar\/29.13.e65"},{"key":"2020022801315721100_R13","doi-asserted-by":"crossref","unstructured":"Zhou L, Thorson JA, Nugent C, Davenport RD, Butch SH, Judd WJ. Noninvasive prenatal RHD genotyping by real-time polymerase chain reaction using plasma from D-negative pregnant women. Am J Obstet Gynecol2005;193:1966-1971.","DOI":"10.1016\/j.ajog.2005.04.052"},{"key":"2020022801315721100_R14","doi-asserted-by":"crossref","unstructured":"Chiu RWK, Poon LL, Lau TK, Leung TN, Wong EM, Lo YMD. Effects of blood-processing protocols on fetal and total DNA quantification in maternal plasma. Clin Chem2001;47:1607-1613.","DOI":"10.1093\/clinchem\/47.9.1607"},{"key":"2020022801315721100_R15","doi-asserted-by":"crossref","unstructured":"Rijnders RJ, Christiaens GC, Bossers B, van der Smagt JJ, van der Schoot CE, de Haas M. Clinical applications of cell-free fetal DNA from maternal plasma. Obstet Gynecol2004;103:157-164.","DOI":"10.1097\/01.AOG.0000103996.44503.F1"}],"container-title":["Clinical Chemistry"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/academic.oup.com\/clinchem\/article-pdf\/52\/12\/2211\/32687281\/clinchem2211.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"http:\/\/academic.oup.com\/clinchem\/article-pdf\/52\/12\/2211\/32687281\/clinchem2211.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,2,28]],"date-time":"2020-02-28T06:34:17Z","timestamp":1582871657000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/clinchem\/article\/52\/12\/2211\/5626694"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2006,12,1]]},"references-count":15,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2006,12,1]]},"published-print":{"date-parts":[[2006,12,1]]}},"URL":"https:\/\/doi.org\/10.1373\/clinchem.2006.074997","relation":{},"ISSN":["0009-9147","1530-8561"],"issn-type":[{"value":"0009-9147","type":"print"},{"value":"1530-8561","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2006,12,1]]},"published":{"date-parts":[[2006,12,1]]}}}