HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Data Supplement A correction has been published All Versions of this Article: clinchem.2005.052340v1 51/10/1786    most recent Submit an electronic Letter to the Editor about this paper Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (13) Citing Articles via Google Scholar Google Scholar Articles by Wong, B. C.K. Articles by Lo, Y.M. D. Search for Related Content PubMed PubMed Citation Articles by Wong, B. C.K. Articles by Lo, Y.M. D. Related Collections Molecular Diagnostics and Genetics

Circulating Placental RNA in Maternal Plasma Is Associated with a Preponderance of 5' mRNA Fragments: Implications for Noninvasive Prenatal Diagnosis and Monitoring

Departments of¹ Chemical Pathology and ² Obstetrics and Gynecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China.

^aAddress correspondence to this author at: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Rm 38023, 1/F Clinical Sciences Bldg, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong SAR, China. Fax 852-2194-6171; e-mail loym{at}cuhk.edu.hk.

Background: The molecular characteristics of placental RNA circulating in maternal plasma are unknown. We investigated the integrity of circulating placental RNA in maternal plasma and tested the relevance of plasma RNA integrity for noninvasive prenatal diagnosis.

Methods: Six different placental transcripts and mRNA of the housekeeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were quantified for the 5' and 3' regions in maternal plasma by 1-step real-time reverse transcription-PCR (RT-PCR) assays. This quantitative strategy was validated by 2-step RT-PCR and serial dilution experiments. The rates of detection by the 5' and 3' assays for the ß-subunit of human chorionic gonadotropin (ßhCG) were assessed in maternal plasma samples collected from different gestational periods.

Results: For 5 of the 7 genes, the plasma mRNA concentrations measured by the 5' amplicons were significantly higher than those measured by the corresponding 3' amplicons. Every transcript under study demonstrated a higher rate of detection in the 5' assay than in the 3' assay in maternal plasma. In particular, the detection rate of ßhCG mRNA in maternal plasma was increased throughout gestation when the 5' assay was used.

Conclusions: Circulating placental RNA is associated with a preponderance of 5' mRNA fragments in maternal plasma. Apart from its intrinsic biological interest, this information could have important implications for the development of new assays targeting fetal RNA markers for noninvasive prenatal diagnosis and monitoring.

The following articles in journals at HighWire Press have cited this article:

				F Salway, P. Day, W. Ollier, and T. Peakman Levels of 5' RNA tags in plasma and buffy coat from EDTA blood increase with time Int. J. Epidemiol., April 1, 2008; 37(suppl_1): i11 - i15. [Abstract] [Full Text] [PDF]

				N. J. Park, Y. Li, T. Yu, B. M.N. Brinkman, and D. T. Wong Characterization of RNA in Saliva Clin. Chem., June 1, 2006; 52(6): 988 - 994. [Abstract] [Full Text] [PDF]

				B. C.K. Wong, K.C. A. Chan, A. T.C. Chan, S.-F. Leung, L. Y.S. Chan, K. C.K. Chow, and Y.M. D. Lo Reduced Plasma RNA Integrity in Nasopharyngeal Carcinoma Patients Clin. Cancer Res., April 15, 2006; 12(8): 2512 - 2516. [Abstract] [Full Text] [PDF]