Methods and Processes for Non-Invasive Assessment of Genetic Variations

A method for detecting one, two, three or four copies of a fetal chromosome or portion thereof in a sample, comprising:

• (a) contacting a sample comprising circulating cell-free nucleic acid from a human pregnant female bearing a fetus with a collection of primer pairs under amplification conditions, wherein each primer pair is specific for nucleic acid sequences located within a target polynucleotide in chromosome 13, chromosome 18 or chromosome 21, and there are at least 4 primer pairs for amplifying target nucleotides for each chromosome, wherein the target polynucleotides are in:
• chromosome 13 polynucleotides of SEQ ID NOs:
• 193-198, 200-204, 206, 208-210, 212-215, or complement thereof;
• chromosome 18 polynucleotides of SEQ ID NOs:
• 216-218, 220-230, 232, or complement thereof;
• and
• chromosome 21 polynucleotides of SEQ ID NOs:
• 234, 236, 238-240, 242-246, 248-253, 255, 256, or complement thereof;
• thereby generating amplicons
• (b) determining amounts of target polynucleotides in each of chromosome 13, chromosome 18 and chromosome 21 for from amplicons in (a);
• and
• (c) quantifying from the amounts of target polynucleotides, one, two, three or four copies of one or more of chromosome 13, chromosome 18, chromosome 21, or portion thereof, in the fetus.