A method and system for detecting chromosome ploidy abnormalities

Abstract

The invention belongs to the technical field of medical chromosomal abnormality information detection, and discloses a chromosomal ploidy abnormality detection method and detection system. After preprocessing the sample data, the reads value of each chromosome of the sample is obtained, and the sample is tested by t-test, and Estimate the expected value and standard deviation of the statistic Ratio under the null hypothesis; after obtaining the standard deviation and expected value, calculate the Ratio value: after calculating the Ratio value, use different reference groups to calculate different z values ​​for different types of chromosomes; calculate After different z values, use the decision tree classification algorithm to detect the sex chromosomes. When the present invention selects the reference group, the selection of the reference group is set according to the detected objects; the present invention performs a large number of preprocessing methods such as deduplication on the data in the early stage, and the decision tree algorithm and the random forest algorithm make the detection results more accurate.

Description

technical field [0001] The invention belongs to the technical field of medical chromosome abnormality information detection, and in particular relates to a detection method and a detection system for chromosome multiple abnormality. Background technique [0002] Before the 1990s, the main method for detecting Down's syndrome was invasive means, such as umbilical cordocentesis, which is to collect fetal blood through maternal abdominal wall puncture under the guidance of ultrasound to obtain fetal information. The advantage of invasive screening is that it is easy and quick to operate. The disadvantage is that the false positive is high, and there may be complications such as hemorrhage, fetal bradycardia, fetal death, infection, early placental separation, fetal blood entering the maternal circulation, and the probability of complications is about 1%. . [0003] After the 1990s, the most common detection methods relied on serological screening and B-ultrasound examination,...

AI Technical Summary

Problems solved by technology

[0011] (1) In the existing chromosome detection technology, the abnormal information of chromosome monosomy or polysome cannot be accurately detected;

[0012] Existing technology also has the problem of inaccurate sex chromosome detection

[0013] (2) Some polyploid detection methods rely too much on the alignment results of completely consistent sequences, and information that cannot be located is considered invalid information

[0014] (3) Some polyploid detection methods only detect specific target chromosomes, and do not include the detection of sex chromosome abnormalities, and the detection range is too small

[0017] Because the test is carried out by collecting samples from pregnant women, it is inevitable that the sample contains the gene sequence of the mother, and the gene sequence of the mother accounts for more than 80% of the total sample, the noise will be very large, and it is difficult to extract effective information

[0018] The human gene sequence is composed of ATCG bases, it is difficult to distinguish the difference between the genes of the mother and the baby, so the noise is difficult to remove, which can only be detected in the noise

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