Methods for detecting aneuploidy
The invention generally relates to methods for determining aneuploidy of cells with respect to a control sample. In certain embodiments, the method involves exposing a sample to a plurality of probes capable of capturing DNA from at least one chromosome suspected of having an altered copy number, and at least one control DNA sample known or suspected to have a stable copy number, capturing and sequencing DNA that binds to the probes, calculating a chromosomal read fraction; determining a sample specific scaling factor; scaling the chromosomal read fractions, normalizing the scaled read fractions, and determining a copy number state of at least one chromosome.
1. A method for determining copy number states of chromosomes in a sample, the method comprising the steps of:
extracting DNA from an embryo-derived sample suspected to include at least one chromosome with an altered copy number;
sequencing the DNA to generate sequence reads, wherein sequencing includes fragmenting the DNA into sequences of at least 300 base pairs to generate the sequence reads;
obtaining read counts as a number of the sequence reads that map to each chromosome;
calculating chromosomal read fractions as the fraction per chromosome of a total of the read counts;
correcting an error caused by interdependence in the chromosomal read fractions by multiplying each chromosomal read fraction by a scaling factor that arithmetically minimizes a sum of distances between the read fractions and respective nearest whole number multiples of control euploid read fractions to obtain scaled read fractions;
normalizing the scaled read fractions by estimating the exact number of each chromosome in a given sample; and
calling a copy number for the embryo-derived sample using the normalized scaled read fractions from each chromosome.
2. The method of claim 1 , further comprising determining a copy number state for each chromosome.
3. The method of claim 1 , further comprising the step of diagnosing embryonic aneuploidy.
4. The method of claim 1 , further comprising the step of diagnosing fetal aneuploidy.
5. The method of claim 1 , wherein the sequencing comprises a next-generation sequencing method or a FAST-SeqS sequencing method.
6. The method according to claim 1 , wherein the sample comprises blood or plasma.
7. The method of claim 1 , further comprising the step of diagnosing tumor cell aneuploidy.
8. The method of claim 1 , wherein sequencing comprises a next-generation sequencing method.
9. The method of claim 1 , wherein the sample comprises blood.
10. The method of claim 1 , wherein the sample is at least one of: skin tissue, endometrial tissue, trophectoderm biopsy-derived tissue, nasal passage tissue, CNS tissue, neural tissue, eye tissue, liver tissue, kidney tissue, mammary gland tissue, placental tissue, gastrointestinal tissue, musculoskeletal tissue, genitourinary tissue, or bone marrow.
11. The method of claim 1 , further comprising isolating the DNA.