DNA Chip Construction And Application For Birth Defect

China is a populous country with high incidence of birth defects.According to the latest research report,the occurrence of birth defects was 5.6%,with nearly 900,000 birth defects in children born each year in china.Serious birth defects can bring death or permanent disability,which greatly affects the quality of the population and family relations,as well as increasing the burden on society.Birth defects can be caused by genetic and/or environmental factors.Studies have shown that genomic copy number variations is important genetic factors causing birth defects.Currently,it is a common practice of all countries to prevent birth defects by genetic counseling and prenatal diagnosis of chromosomal abnormalities in the baby's birth.Conventional forms of cytogenetic analysis such G-banded chromosome analysis and rapid FISH(fluorescence in situ hybridization)have been widely used in prenatal diagnosis of genetic diseases and made a significant contribution for preventing birth defect.Nevertheless,there are many limitations apply in the field of diagnosing birth defects such low resolution,low throughput,time-consuming and complicated to operate.Array comparative genomic hybridization(aCGH)offers rapid,high-throughput and high-resolution on minimal amounts of DNA,which is applied to detect non-balanced chromosomal abnormalities by detecting its genomic copy number variations(CNVs).A large number of CNVs can be detected in a single experiment.According to the research,many serious birth defects were associated with copy number abnormalities.Therefore,aCGH also play an important role in gene diagnosis of birth defects.aCGH also provides a very powerful tool for cancer research,cancer diagnosis,classification and prognosis valuation.Our lab has genome-wide probe library,this study was designed to construct DNA chip for birth defects by picking out probe of birth defects gene from genome-wide probe library,and built a platform about array comparative genomic hybridization technology.We detected CNVs of birth defects by use of the DNA chip,and analyzed clinically relevant genomic gains and losses using blood samples genomic.We have been using PCR technology to amplify the 7254 set of probes for making BD-CA chips and combining the PCR technology with Bst DNA polymerase amplification technology amplified 4222 set of probes for BD chip,as well as made a comparison between their characteristic.We made the DNA chip with direct spotting method,and applied it to a variety of genome samples of birth defects,including congenital deaf,mental retardation and autism.We made a preliminary optimization about the application process of DNA chip,such as cloning and expression of the Bst DNA polymerase which are used to amplify genomic sample,to determine the sample genomic crushing time by ultrasound,improved the hybridization buffer system.Finally,using a variety of software for data integration and analysis,we can know the performance of DNA chip.According to the image signal,we can enhance level of DNA chip applications,and acquire more significant genomic information about birth defects.