METHODS FOR NON-INVASIVE PRENATAL PLOIDY CALLING

摘要

Disclosed herein are methods for determining the copy number of a chromosome in a fetus in the context of non-invasive prenatal diagnosis. In an embodiment, the measured genetic data from a sample of genetic material that contains both fetal DNA and maternal DNA is analyzed, along with the genetic data from the biological parents of the fetus, and the copy number of the chromosome of interest is determined. In an embodiment, the maternal serum is measured using a single-nucleotide polymorphism (SNP) microarray, along with parental genomic data, and the determination of the chromosome copy number is used to make clinical decisions pertaining to the fetus.

主权项

1. A method for determining the number of copies of a chromosome or chromosome segment of interest in the genome of a gestating fetus, the method comprising:
obtaining measured genetic data at a plurality of loci on a chromosome or chromosome segment of interest in the a mixed sample of DNA comprising fetal DNA and maternal DNA; determining, on a computer, a ratio of fetal to maternal DNA in the mixed sample from the measured genetic data; creating a plurality of hypotheses specifying the number of copies of the chromosome or chromosome segment of interest in the fetus; determining, on a computer, the probability of each of the hypotheses using the measured genetic data and the ratio of fetal to maternal DNA; and selecting the hypothesis with the greatest probability, thereby determining the number of copies of the chromosome or chromosome segment of interest in the genome of the fetus.