Patent ID: 8663921

Claim:
A method of determining the presence or absence of a fetal chromosomal aneuploidy, comprising: providing a composition that comprises isolated or purified maternal and fetal nucleic acids molecules from a maternal sample; determining sets of tandem single nucleotide polymorphisms present in specific chromosomes; producing amplicons from the composition comprising the determined sets of tandem single nucleotide polymorphisms; identifying produced amplicons comprising at least 3 different haplotypes of at least one tandem single nucleotide polymorphism (SNP), wherein the single nucleotide polymorphisms in the tandem SNP are at most 250 basepairs apart, and wherein 2 of the 3 haplotypes are present in the maternal nucleic acids and wherein 1 of the 3 haplotypes is not present in the maternal nucleic acids; quantifying the amount of each of the identified amplicons produced from the composition and comprising the 3 different haplotypes; comparing the quantified amounts of each amplicon to one another; comparing the tandem SNPs present in the amplicons so as to identify the chromosomes from which the amplicons are produced; and determining whether the fetus has a chromosomal aneuploidy based on the compared quantified amounts of amplicons in the composition.