文献_2012-Noninvasive prenatal aneuploidy testing of chromosomes 13, 18, 21, X, and Y, using targeted sequencing of polymorphic loci.pdfVIP

DOI: 10.1002/pd.3993 ORIGINAL ARTICLE Noninvasive prenatal aneuploidy testing of chromosomes 13, 18, 21, X, and Y, using targeted sequencing of polymorphic loci 1† 1† 1† 1† 1† 1 1 Bernhard Zimmermann , Matthew Hill , George Gemelos , Zachary Demko , Milena Banjevic , Johan Baner , Allison Ryan , Styrmir Sigurjonsson 1 1 1 2 1* , Nikhil Chopra , Michael Dodd , Brynn Levy and Matthew Rabinowitz 1Natera Inc, San Carlos, CA, USA 2Department of Pathology and Cell Biology, Columbia University, New York, NY, USA *Correspondence to: Matthew Rabinowitz. E-mail: mrabinowitz@ †These authors contributed equally to this work. ABSTRACT Objective This study aims to develop a noninvasive prenatal test on the basis of the analysis of cell-free DNA in maternal blood to detect fetal aneuploidy at chromosomes 13, 18, 21, X, and Y. Methods A total of 166 samples from pregnant women, including 11 trisomy 21, three trisomy 18, two trisomy 13, two 45, X, and two 47,XXY samples, were analyzed using an informatics-based method. Cell-free DNA from maternal blood was isolated, amplified using a multiplex polymerase chain reaction (PCR) assay targeting 11 000 single nucleotide polymorphisms on chromosomes 13, 18, 21, X, and Y in a single reaction, and sequenced. A Bayesian-based maximum likelihood statistical method was applied to determine the chromosomal count of the five chromosomes interrogated in each sample, along with a sample-specific calculated accuracy for each test result. Results The algorithm correctly reported the chromosome copy number at all five chromosomes in 145 samples that passed a DNA quality test, for a total of 725/725 correct calls. The average calculated accuracy for these samples was 99.92%. Twenty-o