A method for detecting chromosomal microdeletions and microduplications in human embryos

Abstract

The invention relates to a method for detecting chromosome microdeletion and micro-duplication of a human embryo. The method comprises the following steps of performing whole genome amplification on cells cultured in vitro, interrupting DNA (deoxyribonucleic acid) molecules, and sequencing DNA fragments to obtain sequencing reads; comparing the sequencing reads with a reference sequence, and positioning the sequencing reads on the reference sequence; screening non-repeated areas of the reference sequence, and reserving the non-repeated areas; establishing a matrix of read number in windows through normal samples, analyzing the data of the normal samples, performing statistics on the read number of all the windows in the non-repeated areas, and establishing a probability matrix of the read number and chromosome enpeoids; calculating the copy number, i.e., the A / B / C state, of loci; selecting m continuous loci, i.e., the A state, as micro-duplication loci, and selecting m continuous loci, i.e., the C state, as microdeletion loci; contrasting the micro-duplication loci and the microdeletion loci with the existing CNV (copy number variation) and disease database, performing basic gene annotation and gene function analysis which relates to deletion parts, and annotating with a microdeletion syndrome disease type.

Description

Technical field [0001] The invention relates to the field of molecular cell biology, in particular to a method for detecting human embryo chromosome microdeletion and microduplication, which can detect the copy number variation of human embryo blastocyst trophoblast cell chromosome DNA fragments. Background technique [0002] Chromosome microdeletion / microduplication refers to a deletion or duplication with a length of 1.5kb-10Mb on a chromosome. Human chromosome microdeletion / microduplication syndrome is caused by the occurrence of small deletions or duplications in human chromosomes, that is, DNA fragment copy number variation, abbreviated as CNV, which causes complex phenotypic diseases, which can lead to serious diseases and abnormalities, such as congenital Sexual heart disease, growth retardation, limb deformities, etc. Common microdeletion syndromes include 22q11 microdeletion syndrome, cat barking syndrome, Angelman syndrome, AZF deletion and so on. [0003] The 2009 "Res...

AI Technical Summary

Problems solved by technology

This method is simple and easy, but the disadvantage is that it can only detect known sites, and only a few sites can be detected at a time

[0012] Although, in 2014, Wells et al. reported the use of NGS technology for chromosome CNV detection and achieved full genome coverage, the resolution of this technology is still not high enough, and it can only detect chromosome aneuploidy and cannot detect chromosome microdeletions / microrepetition

The algorithm it adopts is mean value comparison. The disadvantage of this algorithm is that it requires long DNA fragments and calculates the average value for the entire chromosome, so it can only do aneuploidy analysis in the chromosome range.

[0013] In summary, the current limiting factors for the detection of chromosomal microdeletions / microduplications mainly include low resolution, inability to cover the whole genome, low throughput and high cost.

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