CN106929595B

CN106929595B - System and method for identifying balanced translocation carrying state of embryo

Info

Publication number: CN106929595B
Application number: CN201710294366.8A
Authority: CN
Inventors: 徐家伟; 孙莹璞; 陆思嘉; 牛文彬; 高玉梅; 戴善军
Original assignee: Shanghai Yikon Clinical Laboratory Co ltd; First Affiliated Hospital of Zhengzhou University
Current assignee: Shanghai Yikon Clinical Laboratory Co ltd; First Affiliated Hospital of Zhengzhou University
Priority date: 2017-04-28
Filing date: 2017-04-28
Publication date: 2021-03-30
Anticipated expiration: 2037-04-28
Also published as: CN106929595A

Abstract

The invention relates to a system and a method for identifying the balanced translocation carrying state of an embryo, wherein the system comprises the following units: (1) a sampling unit; (2) a sequencing unit; (3) a copy number analysis unit; (4) SNP analysis unit and (5) alignment unit. The system and the method adopt a single sperm amplification mode and a targeted PCR mode to search the fracture site, have relatively simple and easy operation, can effectively reduce PCR amplification bias, have high sensitivity, and can simultaneously provide information of embryo aneuploidy screening and balanced translocation carrying states.

Description

System and method for identifying balanced translocation carrying state of embryo

Technical Field

The invention relates to the field of biotechnology, genome sequence analysis and particularly relates to a method for identifying an embryo equilibrium translocation carrying state.

Background

Medical genetics is the leading and emerging discipline in medicine today. Is the subject of main research in life science. Medical genetics mainly utilizes DNA technology to study the relationship of diseases to genes. Novel diagnostic techniques and therapeutic methods are developed. Can provide more efficient novel medical services for early diagnosis of diseases, prevention of birth defects and diagnosis and treatment of difficult and complicated diseases at a molecular level. The development of medical genetics is not free from rapid advances in various technologies, particularly the development of high-throughput sequencing technologies in recent years.

The birth of the high-throughput sequencing technology can be said to be an event with milestone significance in the field of genomics research. This technology has allowed the single base cost of nucleic acid sequencing to fall dramatically compared to the first generation of sequencing technologies, which has been the end of the last century where human genome projects costed $ 30 million to decode human life codes, as exemplified by human genome sequencing, while the second generation of sequencing has allowed human genome sequencing to enter the ten thousand (U.S.) metagenomic era. Such low cost single base sequencing allows one to implement more species of genome projects to decipher the genome genetic code of more biological species. Meanwhile, in the species with the sequenced genome sequence, the other varieties of the species can be subjected to large-scale whole genome re-sequencing.

The development of high-throughput sequencing technology also responds to the arrival of the era of precise medical treatment, which is based on personal genome information and combines related internal environment information such as proteome, metabolome and the like to design a health management and disease treatment scheme for people in a quantitative manner so as to achieve a customized medical treatment mode with maximized treatment effect and minimized side effect. It can be determined that the precise medicine is the convergence and fusion application in medical clinical trials, which is the leading direction of the development of medical science and technology. Emphasis is placed in the national "precision medical research" focus specialties: the accurate medical research layout is systematically strengthened, the breakthrough of the major disease prevention and control technology is accelerated, the dominant right of future medical and related industry development is occupied, and a new driving force for the development of the life health industry in China is made in a key point.

The chromosome abnormality is divided into structural abnormality and numerical abnormality, the chromosome numerical abnormality generally causes obvious phenotype, and the chromosome numerical abnormality can be effectively detected through B ultrasonic screening and the like. Patients with chromosomal abnormalities generally do not have a phenotype and are usually diagnosed with repeated abortions or infertility screenings when they are born to the next generation. Structural chromosomal abnormalities are mainly classified into: balanced translocation, roche translocation and chromosomal inversion. The balanced translocation of chromosomes refers to the mutual exchange of two chromosomes after the breakage, only the position is changed, no visible increase and decrease of chromosome segments are generated, and the incidence rate in the population is 0.1-0.2%.

Pre-implantation genetic diagnosis (PGD) of assisted reproductive embryos is an effective treatment for structural chromosomal abnormalities. PGD diagnosis and treatment is a better clinical treatment strategy for patients with chromosome structural abnormality, and for patients with balanced translocation, whether embryos of the patients carry balanced translocation inherited from parents cannot be detected, so that the patients with balanced translocation carriers still have carriers with balanced translocation in offspring after PGD assisted pregnancy, and still face the problems of repeated abortion or primary infertility and the like after adults. The PGD follow-up data of my center shows: about 10% of the offspring of PGD assisted post-pregnancy patients with balanced chromosomal translocations remain carriers of balanced translocations. How to distinguish whether the embryo of a patient carries balanced translocation or not before embryo implantation and block the vertical transmission of the balanced translocation is a great scientific problem faced by the PGD technology.

The application of the FISH technology and genetic diagnosis before embryo implantation effectively investigate the imbalance of the embryo and improve the pregnancy rate of patients with abnormal chromosome structures, but the FISH operation process is more complex, the detection sites are few, and only aneuploidy of a few chromosomes can be detected; each balanced translocation requires the design of specialized probes to distinguish balanced translocation carriers from normals; the method has long detection period, cannot detect microdeletion and microduplication, cannot perform whole-gene chromosome aneuploidy screening, cannot perform clinical application limited by genetic diagnosis before implantation of single-gene genetic disease embryos, and the like, each balanced translocation needs to design a special probe, is complicated in operation method and limited in detection range, and multi-center random contrast research finds that the FISH technology is applied to PGS and does not effectively improve the pregnancy rate of patients. The FISH technology cannot screen the whole genome chromosome, so the whole genome screening of the embryo is necessary.

At present, in the field of genetic diagnosis before embryo implantation, CGH can carry out aneuploidy screening on embryos, Array CGH, SNP Array and NGS can cover the whole genome range, the operation process is simpler, the detection flux is high and is widely adopted in clinic, but the high-flux screening methods can only detect the unbalanced translocation of chromosomes: i.e., deletion or duplication of a chromosome fragment; the SNP array method has more sites than CGH, has good coverage, can better screen embryo aneuploidy, and has a few reports that the SNP array is used for linkage analysis to diagnose the embryo carrying state, but the translocation sites can not be determined, and the embryo carrying state can not be diagnosed under the condition that the translocation embryo is not formed in an unbalanced manner. Therefore, the clinical application of CGH and SNP array in the screening of the embryo translocation carrying state has certain limitation.

At present, the breaking point is obtained by a Mate-pair library strategy adopted for distinguishing balanced translocation carriers, the library building difficulty of the method is relatively higher, a large amount of PCR is needed to be carried out when the specific breaking point position is obtained, and then a generation of sequencing verification is adopted, so that the cost is high and the time consumption is long. The method adopts a microdissection mode to obtain the equilibrium translocation breakpoint, the microdissection instrument is required for operation, the microdissected fragments can be subjected to subsequent amplification experiments after being purified, the method has high technical difficulty, complicated process and relatively low success rate.

In addition to the above technical shortcomings, none of the above detection techniques can accurately determine the state of equilibrium translocation carryover/non-carryover of an embryo. Therefore, there is an urgent need in the art to develop a method for more effectively and comprehensively identifying the carrying/non-carrying of balanced translocation of embryos, and to improve the accuracy of judging balanced translocation.

Disclosure of Invention

Aiming at the defects and actual requirements of the prior art, the invention provides a system and a method for identifying the balanced translocation carrying state of an embryo, the system and the method adopt a single sperm amplification mode and a targeted PCR mode to search a fracture site, the operation is relatively simple and easy, the PCR amplification bias can be effectively reduced, the sensitivity is high, and the information of embryo aneuploidy screening and the balanced translocation carrying state can be provided at the same time.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a system for identifying the balanced translocation carrying status of an embryo, comprising the following units:

(1) a sampling unit: obtaining a sample to be tested for an embryo, sperm of a father party and DNA of a mother party;

(2) a sequencing unit: selecting single sperm from semen obtained by father, amplifying, constructing library and sequencing;

(3) copy number analysis unit: carrying out chromosome Copy Number (CNV) analysis on the sequencing result to preliminarily determine a chromosome translocation position;

(4) SNP analysis unit: carrying out SNP analysis on a chromosome translocation position and a peripheral position, and comparing a plurality of single sperms to obtain a haplotype of a normal single sperm;

(5) carrying out SNP analysis on the corresponding translocation position and the peripheral position of the chromosome of the maternal side;

(6) an alignment unit: and carrying out SNP analysis on the translocation position and the peripheral position corresponding to the chromosome of the embryo of the sample to be detected, and comparing the analysis result with the normal single sperm haplotype and the SNP information of the maternal side to determine the balanced translocation carrying state of the embryo.

According to the invention, the sample to be tested in step (1) is a biopsy cell of an embryo, the biopsy cell is an ectodermal cell taken from the embryo at a stage from development to blastomere stage or blastocyst stage, and the ectodermal cell may be 1 or a plurality of trophectodermal cells.

According to the present invention, the maternal DNA is any human sample capable of extracting DNA, and is not particularly limited herein, and can be extracted by a person skilled in the art according to experimental needs.

According to the present invention, the number of the selected monosperms of step (2) is 15-30, such as 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30, preferably 18-25, and the specific values between the above values are not exhaustive and the invention is not limited to the specific values included in the range for brevity and conciseness.

According to the invention, the amplification in the step (2) is single cell amplification, and trace nucleic acid in the biopsy cells is amplified through the single cell amplification so as to obtain more nucleic acid for subsequent analysis.

According to the present invention, the single cell Amplification is feasible as a method capable of performing single cell Amplification, and a person skilled in the art can select the single cell Amplification according to experimental needs without limitation, and the present invention employs any one or a combination of at least two of Primer extension PCR (PEP-PCR), Degenerate oligonucleotide Primer PCR (DOP-PCR), Multiple Displacement Amplification (MDA), or Multiple Annealing circular Amplification (MALBAC) technology, preferably Multiple Annealing circular Amplification technology.

According to the invention, after the amplified sample is subjected to library construction by the sequencing in the step (2), a high-throughput sequencing platform is adopted for sequencing, the high-throughput sequencing platform is a second-generation sequencing platform, the second-generation sequencing platform in the field is feasible and is not particularly limited, and the sequencing platform can be selected by a person skilled in the art according to needs, and the sequencing platform can adopt GA, GAII, GAIIx, HiSeq1000/2000/2500/3000/4000, X Ten, X Five, NextSeq500/550, MiSeq, MiSeqDx, MiSeq FGx, MiniSeq and NovaSeq 5000/6000 of Illumina; the present invention is preferably Applied to any one of SOLID from Applied Biosystems, 454FLX from Roche, Ion Torrent, Ion PGM, Ion Proton I/II from Thermo Fisher Scientific (Life Technologies), BGISEQ1000, BGISEQ500, BGISEQ100, BGISEQ50 from Huada Dai Geng Limited, Bioeletron seq 4000 from Boo Bio, DA8600 from Daan Geng Ltd at Zhongshan university, NextSeq CN500 from Beirui and Kangsan, BIGIS from Kearnxin in Shingsu, HYK-PSTAR-IIA from Huanyang, and HiSeq2500 high-throughput sequencing platform from Illumina.

Preferably, the sequencing type is single-ended sequencing and/or double-ended sequencing, preferably single-ended sequencing.

According to the invention, the length of the sequence is not less than 30bp, and may be, for example, 30bp, 40bp, 50bp, 80bp, 100bp, 150bp, 300bp, 500bp, and preferably 50bp, and the specific point values between the above values are not exhaustive, and the invention is not limited to the specific point values included in the range for brevity and conciseness.

According to the invention, the depth of the sequencing is not less than 0.1 times of the genome, for example, 0.1 times, 0.5 times, 1 times, 2 times, 5 times, 10 times, 30 times, 50 times, 100 times, preferably 0.1 times of the genome, and the specific points between the above values are not exhaustive list of the specific points included in the range for reasons of brevity and conciseness.

Preferably, the sequencing method adopts an MALBAC single-cell amplification method and a HiSeq2500 high-throughput sequencing platform of Illumina company, the sequencing type is single-ended sequencing, the sequencing length is 50bp, and the sequencing depth is 0.1 time of the genome.

According to the present invention, the peripheral positions in step (4) are positions within 1-5M of the chromosomal translocation position, such as 1M, 2M, 3M, 4M or 5M, preferably positions within 1-3M of the chromosomal translocation position, and the specific points between the above values are not exhaustive, and the present invention is not limited to the specific points included in the range for brevity and conciseness.

Preferably, the number of SNPs at the surrounding positions is generally more than 30, the number of available sites on each embryo is about 1/3, and the haplotype linkage relationship can be determined by more than 10 available sites, the number of SNPs in the invention is 10-500, for example, 10, 20, 30, 40, 50, 60, 80, 100, 120, 130, 150, 200, 250, 300, 350, 400, 450, 500, preferably 30-100, and the specific points between the above values are limited by space and for the sake of brevity, and the invention is not exhaustive list of the specific points included in the range.

According to the present invention, the method for SNP analysis is a method known in the art, and is not particularly limited herein, and a person skilled in the art can select the method according to needs.

According to the invention, the specific steps of obtaining the normal chromosome haplotype in step (4) are as follows: comparing the single sperm with chromosome duplication or deletion, and subtracting the SNP of the single sperm with translocation from the SNP of the single sperm with translocation deletion to determine the haplotype of normal single sperm.

According to the invention, SNPs at the corresponding translocation positions and the peripheral positions of the mother chromosome in the step (5) are homozygotes.

According to the invention, the specific steps of determining the balanced translocation carrying status of the embryo in the step (6) are as follows: and comparing the haplotype SNP obtained by subtracting the SNP of the maternal side from the SNP of the embryo of the sample to be detected with the normal single sperm haplotype, if the haplotype SNP is consistent, the embryo is a normal embryo, and if the haplotype SNP is inconsistent, the embryo is a carrier embryo.

In a second aspect, the present invention provides a method for detecting an embryo balanced translocation status for non-diagnostic purposes, using a system according to the first aspect, comprising the steps of:

(1) obtaining a sample to be tested for an embryo, sperm of a father party and DNA of a mother party;

(2) selecting single sperm from semen obtained by father, amplifying, constructing library and sequencing;

(3) carrying out chromosome Copy Number (CNV) analysis on the sequencing result to preliminarily determine a chromosome translocation position;

(4) carrying out SNP analysis on a chromosome translocation position and a peripheral position, and comparing a plurality of single sperms to obtain a haplotype of a normal single sperm;

(6) and carrying out SNP analysis on the translocation position and the peripheral position corresponding to the chromosome of the embryo of the sample to be detected, and comparing the analysis result with the normal single sperm haplotype and the SNP information of the maternal side to determine the balanced translocation carrying state of the embryo.

As a preferred technical scheme, the method for detecting the balanced translocation carrying state of the embryo comprises the following steps:

(1) obtaining biopsy cells, paternal semen and maternal DNA of an embryo;

(2) selecting 15-30 single sperms from semen obtained from father, carrying out annealing circular cyclic amplification for multiple times, constructing a library, and then sequencing by adopting a high-throughput sequencing platform;

(3) and (3) carrying out chromosome copy number analysis on the sequencing result, and preliminarily determining the translocation position of the chromosome: the chromosome translocation position is preliminarily judged according to the chromosome copy number analysis and the repeated or missing position of the chromosome;

(4) carrying out SNP analysis in a chromosome translocation position and a peripheral position within 1-5M, and comparing a plurality of single sperms to obtain the haplotype of normal single sperms: comparing the spermatozoa with chromosome duplication or deletion, subtracting the SNP of the translocation-deficient spermatozoa from the SNP of the translocation-2-fold spermatozoa, and determining the haplotype of the normal spermatozoa;

(5) carrying out SNP analysis on the corresponding translocation position of the chromosome of the maternal side and the 1-5M of the peripheral position;

(6) carrying out SNP analysis in the translocation position corresponding to the chromosome of the embryo of the sample to be detected and the peripheral position 1-5M, comparing the analysis result with the normal single sperm haplotype and the SNP information of the maternal side, and determining the balanced translocation carrying state of the embryo: and comparing the haplotype SNP obtained by subtracting the SNP of the maternal side from the SNP of the embryo of the sample to be detected with the normal single sperm haplotype, if the haplotype SNP is consistent, the embryo is a normal embryo, and if the haplotype SNP is inconsistent, the embryo is a carrier embryo.

Compared with the prior art, the invention has the following beneficial effects:

(1) the system and the method of the invention adopt a single sperm amplification mode and a targeted PCR mode to search the fracture site, can accurately position the fracture site to 200kb-500kb, can effectively reduce PCR amplification bias and have high sensitivity;

(2) the system and the method can simultaneously screen the embryo chromosome aneuploidy and excavate the SNP locus in the 2M area near the balanced translocation fracture locus, can simultaneously provide the information of embryo aneuploidy screening and balanced translocation carrying state, and simultaneously determine the translocation position and the embryo aneuploidy;

(3) the system and the method have the advantages of relative simple and easy operation, low cost and easy popularization and application.

Drawings

FIG. 1 is a CNV analysis of sample 6_2_ MAL _ CNV in example 1 of the present invention;

FIG. 2 is a CNV analysis of a sample 12_2_ MAL _ CNV in example 1 of the present invention;

FIG. 3 is a CNV analysis of sample 13_2_ MAL _ CNV in example 1 of the present invention;

FIG. 4 is a CNV analysis of sample 17_2_ MAL _ CNV in example 1 of the present invention;

FIG. 5 is a CNV analysis of embryos in example 1 of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention, the following further describes the technical solutions of the present invention by way of specific embodiments with reference to the drawings, but the present invention is not limited to the scope of the embodiments.

Example 1 System for identifying equilibrium translocation status of embryos

The system for identifying the balanced translocation carrying state of the embryo comprises the following units:

(1) a sampling unit: obtaining biopsy cells, paternal semen and maternal DNA of an embryo;

(2) a sequencing unit: selecting 15-30 single sperms from semen obtained from father, carrying out annealing circular cyclic amplification for multiple times, constructing a library, and then sequencing by adopting a high-throughput sequencing platform;

(3) copy number analysis unit: and (3) carrying out chromosome copy number analysis on the sequencing result, and preliminarily determining the translocation position of the chromosome: the chromosome translocation position is preliminarily judged according to the chromosome copy number analysis and the repeated or missing position of the chromosome;

(4) SNP analysis unit: carrying out SNP analysis in a chromosome translocation position and a peripheral position within 1-5M, and comparing a plurality of single sperms to obtain the haplotype of normal single sperms: comparing the spermatozoa with chromosome duplication or deletion, subtracting the SNP of the translocation-deficient spermatozoa from the SNP of the translocation-2-fold spermatozoa, and determining the haplotype of the normal spermatozoa;

(6) an alignment unit: carrying out SNP analysis in the translocation position corresponding to the chromosome of the embryo of the sample to be detected and the peripheral position 1-5M, comparing the analysis result with the normal single sperm haplotype and the SNP information of the maternal side, and determining the balanced translocation carrying state of the embryo: and comparing the haplotype SNP obtained by subtracting the SNP of the maternal side from the SNP of the embryo of the sample to be detected with the normal single sperm haplotype, if the haplotype SNP is consistent, the embryo is a normal embryo, and if the haplotype SNP is inconsistent, the embryo is a carrier embryo.

Example 2 detection of equilibrium translocation status of embryos

The method for identifying the balanced translocation carrying state of the embryo comprises the following steps:

(1) obtaining biopsy cells, sperm of a father and DNA of a mother, wherein the chromosome of the father is as follows: 46, XY, t (9,21) (q24, q 22.1);

(2) selecting 15-30 single sperms from semen obtained from father, annealing for multiple times, circularly amplifying, constructing library, and sequencing with high-throughput sequencing platform, wherein

samples

6, 12, 13 and 17 are four single sperm samples, and the results are shown in FIGS. 1-4 and Table 1:

TABLE 1

Sample name	Sample bar code	The result of the detection
			6	6_2_MAL_CNV	22,Y,+9(p24.1→qter,～119M,×0),-21(p11.2→q21.1,～14M,×2)
12	12_2_MAL_CNV	22,Y,+9p(pter→p24.1,～9M,×2),-21q(q21.1→p24.1,～28M,×0)
			13	13_2_MAL_CNV	22,Y,+9p(pter→p24.1,～9M,×2),-21q(q21.1→p24.1,～28M,×0)
17	17_2_MAL_CNV	22,Y,+9(p24.1→qter,～119M,×0),-21(p11.2→q21.1,～14M,×2)

(3) And (3) carrying out chromosome copy number analysis on the sequencing result, and preliminarily determining the translocation position of the chromosome: through chromosome copy number analysis, the chromosome repeated or deleted position is preliminarily judged to be the chromosome translocation position chr21, and the accuracy is about 500 kb;

(4) SNP analysis was performed in 1-5M at the chromosomal translocation site and the peripheral sites, and the results are shown in Table 2, and the haplotype of normal single sperm was obtained by comparing a plurality of single sperm: comparing the spermatozoa with chromosome duplication or deletion, subtracting the SNP of the translocation-deficient spermatozoa from the SNP of the translocation-2-fold spermatozoa, and determining the haplotype of the normal spermatozoa;

TABLE 2

(6) carrying out SNP analysis in the translocation position corresponding to the chromosome of the embryo of the sample to be detected and the peripheral position 1-5M, wherein the result is shown in Table 3, comparing the analysis result with the normal single sperm haplotype and the maternal SNP information, and determining the balanced translocation carrying state of the embryo: comparing the haplotype SNP obtained by subtracting the SNP of the maternal side from the SNP of the embryo of the sample to be detected with the normal single sperm haplotype, the CNV result is shown in figure 5, and the result is consistent with the normal chr21 after subtracting the SNP of the maternal side, thus the embryo is a normal embryo.

TABLE 3

In conclusion, the method can simultaneously screen the embryo chromosome aneuploidy and excavate the SNP locus in the 2M area near the balanced translocation fracture locus, can simultaneously provide the information of embryo aneuploidy screening and balanced translocation carrying state diagnosis, and simultaneously determine the translocation position and the embryo aneuploidy.

The applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. A system for identifying the state of a balanced translocation carrier of an embryo comprising the following units:

(3) copy number analysis unit: carrying out chromosome copy number analysis on the sequencing result, and preliminarily determining a chromosome translocation position;

2. The system of claim 1, wherein the sample to be tested in step (1) is a biopsy of an embryo.

3. The system of claim 2, wherein the biopsy cells are ectodermal cells removed from the embryo at a stage of development into a blastomere or a blastocyst.

4. The system of claim 1, wherein the number of single sperm selected in step (2) is 15-30.

5. The system of claim 4, wherein the number of single sperm selected in step (2) is 18-25.

6. The system of claim 1, wherein the amplification of step (2) is single cell amplification.

7. The system of claim 6, wherein the single-cell amplification is any one of or a combination of at least two of pre-amplification primer extension PCR, degenerate oligonucleotide primer PCR, multiple displacement amplification technique, or multiple annealing circular cycle amplification technique.

8. The system of claim 7, wherein the single cell amplification is a multiple annealing circular cycle amplification technique.

9. The system of claim 1, wherein the sequencing of step (2) is performed using a high throughput sequencing platform.

10. The system of claim 9, wherein the sequencing type is single-ended sequencing and/or double-ended sequencing.

11. The system of claim 10, wherein the sequencing type is single-ended sequencing.

12. The system of claim 1, wherein the sequencing is no less than 30bp in length.

13. The system of claim 12, wherein the sequencing is 50bp in length.

14. The system of claim 1, wherein the depth of sequencing is no less than 0.1 times the genome.

15. The system of claim 14, wherein the depth of sequencing is 0.1 times the genome.

16. The system according to any one of claims 1 to 15, wherein the specific steps of preliminarily determining the location of the abnormal chromosomal translocation of step (3) are: the position of chromosome duplication or deletion is preliminarily judged as a chromosome translocation position through chromosome copy number analysis.

17. The system of any one of claims 1-15, wherein the surrounding location of step (4) is a site within 1-5M of a chromosomal translocation position.

18. The system of claim 17, wherein the peripheral location of step (4) is a site within 1-3M of a chromosomal translocation position.

19. The system of claim 17, wherein the number of SNPs at the surrounding locations is 10-500.

20. The system of claim 19, wherein the number of SNPs at the surrounding locations is 30-100.

21. The system of claim 1, wherein the SNP analysis is performed by any one or a combination of at least two of designing probe chip capture sequencing, designing primers for sequencing amplicons at one generation, or designing primers for sequencing amplicons at the second generation.

22. The system of claim 1, wherein the step (4) of obtaining the normal chromosome haplotype comprises the following steps: comparing the single sperm with chromosome duplication or deletion, and subtracting the SNP of the single sperm with translocation from the SNP of the single sperm with translocation deletion to determine the haplotype of normal single sperm.

23. The system according to claim 1, wherein the SNPs of the corresponding translocation position and the peripheral position of the chromosome of the maternal side in step (5) are homozygotes.

24. The system of claim 1, wherein the specific steps of determining the balanced translocation carrying status of the embryo in step (6) are as follows: and comparing the haplotype SNP obtained by subtracting the SNP of the maternal side from the SNP of the embryo of the sample to be detected with the normal single sperm haplotype, if the haplotype SNP is consistent, the embryo is a normal embryo, and if the haplotype SNP is inconsistent, the embryo is a carrier embryo.