Detection method of chromosome copy number variation

Abstract

The invention provides a detection method of chromosome copy number variation. The detection method comprises the following steps: preparing cell-free DNA from body fluid of a parent body with an appendage and taking the cell-free DNA as a sample to be detected; preparing cell-free DNA from body fluid of a normal parent body without appendages and taking the cell-free DNA as a check sample; comparing to a reference genome sequence after all sequencing is finished; counting matching number and calculating z value; determining that cnv originates from the appendage if the length of the sample to be detected is smaller than the absolute value of the z value of a DNA sequence of N bp and greater than the absolute value of the z value of all DNA sequences of the sample to be detected in the same window; and determining that the cnv originates from the parent body if the length of the sample to be detected is not smaller than the absolute value of the z value of the DNA sequence of N bp and not greater than the absolute value of the z value of all the DNA sequences of the sample to be detected in the same window. By the detection method, whether the cnv originates from the parent body or the appendage can be judged effectively, accuracy of the result of existing non-invasive detection can be the same with that of the result of the traditional intrusion detection, loss caused by false positive is avoided effectively, and meanwhile, the detection method is easy to operate and has application value.

Description

technical field [0001] The invention belongs to the field of biological detection, and in particular relates to a detection method for chromosome copy number variation. Background technique [0002] Chromosomal copy number variation (hereinafter abbreviated as cnv) can cause diseases. There are many common diseases caused by cnv, for example: trisomy 21, patients have 3 chromosomes 21, while normal people only have 2; Syndrome, caused by deletion of chromosome 15 q11-q13; Turner syndrome, chromosome is XO type (that is, chromosome 45, X). The occurrence of these diseases has brought great suffering to the patients themselves and their families. Therefore, China is currently devoting itself to the development of detection methods for chromosomal copy number variation, especially the detection of fetal cnv, so as to fundamentally prevent the occurrence of diseases. [0003] Because the risk of fetus suffering from diseases caused by CNV increases with the growth of mother's ...

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Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a method that can distinguish chromosome copies in mixed DNA samples in view of the defect that the interference of maternal cnv cannot be ruled out to cause higher false positive results when cnv detection is performed on mixed samples from the mother. The detection method of chromosome copy number variation whether it comes from the mother (the mother is the normal tissue of the pregnant woman or the tumor patient itself) or from the appendage (the appendage is the fetus or tumor tissue)

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