A Fetal Chromosome Detection System Based on DNA Variation Counting

A chromosome and variant number technology, applied in the field of medical testing, can solve problems such as low coverage depth, missed detection of chromosome 3, and insufficient accuracy, and achieve the effect of improving sequencing depth, reducing adverse effects, and increasing the range of genetic diseases

Active Publication Date: 2020-04-07
苏州首度基因科技有限责任公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because the selection of DNA fragments in the previous method is completely random and the coverage depth is low, for a specific region on the chromosome, there is no guarantee that DNA fragments will be detected and there will be enough DNA fragments for subsequent analysis, so this method cannot accurately detect small fragments. Chromosomal abnormalities
[0005] A disadvantage of this method is that the detection accuracy is not enough
When the proportion of DNA fragments from the fetus is relatively small (eg, less than 2%), the detection of chromosome 3 may miss detection (false negative)

Method used

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  • A Fetal Chromosome Detection System Based on DNA Variation Counting

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0064] Example 1 A method for detecting fetal chromosomes based on DNA variation counting

[0065] (1) Use the Cell-Free DNA BCT test tube of STRECK Company to collect 5ml of peripheral blood of the 5-week pregnant woman to be tested according to the instruction manual of the corresponding equipment, and use the QIAamp Circulating Nucleic Acid Kit kit of QIAGEN Company to extract according to the instruction manual of the corresponding kit Plasma cell-free DNA in the sample to be tested;

[0066] (2) Use the Nextseq500 high-throughput sequencing instrument of Illumina to sequence the DNA obtained in step (1) to obtain the short sequence data of the plasma cell-free DNA of the pregnant woman;

[0067] (3) positioning the short sequence obtained in step (2) to the position with the highest similarity on the long sequence of 24 chromosomes in the human genome;

[0068] (4) Use bwa and GATK software to calculate the characters and character strings with differences in the corresp...

Embodiment 2

[0078] Example 2 A fetal chromosome detection method based on DNA variation counting

[0079] (1) Use the Cell-Free DNA BCT test tube of STRECK Company to collect 5ml of peripheral blood of the 10-week pregnant woman to be tested according to the instruction manual of the corresponding equipment, and use the QIAamp Circulating Nucleic Acid Kit kit of QIAGEN Company to extract according to the instruction manual of the corresponding kit For the plasma free DNA in the sample to be tested, use the KAPA Hyper Prep Kit kit from KAPA Biosystems to build a library for the extracted plasma free DNA according to the corresponding kit instruction manual. During the library construction process, use probe primers from DNA sequences of the same DNA template have the same probe;

[0080] (2) Use the Nextseq500 high-throughput sequencing instrument of Illumina to sequence the DNA sample library obtained in step (1), and obtain the short sequence data of the plasma cell-free DNA of the pregn...

Embodiment 3

[0091] Example 3 A Fetal Chromosome Detection System Based on DNA Variation Counting

[0092] Including the following six modules: DNA short sequence data input module, short sequence positioning module on long sequence, sequence difference search module, difference screening module, counting module 1, counting module 2, the modules are electrically connected in sequence; The DNA short sequence data input module inputs the short sequence data from the free plasma DNA of pregnant women; the short sequence positioning module on the long sequence locates the short sequence of the free plasma DNA of pregnant women input by the DNA short sequence data input module to the human genome The position with the highest similarity on the long sequence of the 24 chromosomes; the module for finding sequence differences, based on the output of the short sequence positioning module on the long sequence, compares the short sequence of the plasma cell-free DNA of pregnant women with the correspo...

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Abstract

The invention provides a fetus chromosome detecting method based on DNA variation counting. The method comprises the steps of obtaining and sequencing free DNA of plasma in a peripheral blood sample of a pregnant woman, comparing the free DNA of the plasma with human reference sequences, namely DNA long sequences on 24 chromosomes, counting the number of variation in the free DNA of the plasma andconducting comparison. The invention further discloses a system for achieving the detecting method. The system comprises a DNA short sequence data input module, a module for positioning short sequences on the long sequences, a module for founding sequence difference, a difference screening module, a first counting module and a second counting module, wherein the modules are sequentially and electrically connected. According to the fetus chromosome detecting method based on DNA variation counting and the system for achieving the method, by detecting chromosomes in peripheral blood of the pregnant woman, whether there is chromosome abnormality or not in a fetus is judged, thus harmful effects on the pregnant woman and the fetus in a detecting process are greatly reduced, and by calculatingthe variation number to judge the chromosome abnormality of the fetus, compared with a method that a sequence number is calculated simply, the fetus chromosome detecting method based on DNA variationcounting is more accurate.

Description

technical field [0001] The invention relates to the field of medical detection, in particular to a non-invasive prenatal biological information detection system. Background technique [0002] The incidence of 21, 13, and 18 chromosome aneuploid fetuses is about 1 / 500. Children with these diseases will bring a heavy burden to the family and society in the future. At present, non-invasive prenatal detection technology has been applied and promoted, and the accuracy is as high as 99.9%, most of the fetuses with chromosomal aneuploidy can be detected. However, according to the "China Birth Defect Prevention Report 2012" issued by the Ministry of Health, the incidence of birth defects in my country is close to the average level of the world's medium-importing countries, about 5.6%, and the number of new birth defects is about 900,000 cases every year. Visible birth defects accounted for about 250,000 cases, accounting for about 1.5% of babies, and 19.1% of infant deaths were dire...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C12Q1/6883C12Q1/6869
CPCC12Q1/6869C12Q1/6883C12Q2600/156C12Q2535/122
Inventor 唐元华
Owner 苏州首度基因科技有限责任公司
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