Method for testing chromosome 22q11.2 microdeletion and microduplication

Abstract

The invention pertains to the filed of biological engineering and discloses a method for testing chromosome 22q11.2 microdeletion and microduplication; the testing method comprises the steps of: extracting genome DNA and conducting multiplex fluorescent quantitative PRC multiplex amplification; a multiplex amplification system comprises an internal reference G6PDH and 5 STR markers including D22S873, 22D_5_1, 22D_4_5, 2D_4_4 and 22 D_4_3; PCR amplified products are taken and modified to convert a double-chain product into a single-chain product on which a capilary electrophoretic analysis can be conducted; the capilary electrophoresis is adopted to analyze the length and yield of the modified product; and a quantity ratio analyzing method and / or a method of analyzing the position and quantity of peaks are adopted to judge whether the chromosome is normal and whether microdeletion or microduplication exists. The method can improve the testing reliability, shorten the testing time, lower the testing cost and be convenient for clinical use on large scale.

Description

technical field [0001] The invention belongs to the field of bioengineering and relates to a method for measuring micro-deletion and micro-duplication in chromosome 22q11.2 region. Background technique: [0002] The incidence rate of 22q11 microdeletion population is about 1 / 4000, and it is the most common genomic abnormality syndrome. The most common clinical manifestation is congenital heart defect (CHD). Other clinical manifestations include: facial deformity, immune deficiency, hypercalcemia , skeletal abnormalities, urinary system deformities, mild learning disabilities, etc. The most common CHDs are interrupted aortic arch, tetralogy of Fallot, ventricular septal defect, and persistent arterial trunk. Analysis of 22q11 microdeletion in CHD can not only explore the molecular mechanism of CHD, but also help in clinical diagnosis, genetic counseling and prenatal diagnosis. [0003] Although foreign countries have explored the relationship between 22q11 microdeletion and...

AI Technical Summary

Problems solved by technology

However, as a semi-quantitative method, its false positive rate is inevitable

And its detection cost is high, it is difficult to promote on a large scale

[0005] The common disadvantage of the above methods for testing chromosome copy number changes is the uncertainty of the results

FISH technology is limited by the hybridization fragment of the probe, and the analysis of small deletions in chromosomal loci is prone to missed diagnosis. The judgment result of STRP analysis usually depends on the heterozygous band, and is affected by the heterozygosity of the target sequence and the analysis results of parental samples. Its positive rate is not completely satisfactory, and MLPA is a semi-quantitative method, its false positive rate is inevitable

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