Application Of Chromosome Microarray Analysis In The Diagnosis Of Children With Unexplained Intellectual Disability/developmental Delay

Objective To explore the role of chromosome microarray analysis in the diagnosis of children with intelligence and development problems without definite etiology and analyze the clinical significance of copy number variation in genetic diagnosis Methods From June,2018 to December,2019,149 children with ID/DD of unknown origin were diagnosed in the Department of Pediatric Neurorehabilitation,Anhui Children’s Hospital.2ml of peripheral blood samples were collected,and the copy number of children was analyzed by chromosome microarray technology.The original sample data was checked and matched with the whole human genome,and the relevant database was queried for comparison.And sort out the relevant clinical data.Results Among the 149 children,the number of men and children is 1.2 times the female child.149 children with chromosomal microarray were detected in 36 cases of pathogenic copy number variation(CNV),and 26 micro-repetition / micro-missing syndrome were explicitly recorded in the database.The fragment size ranges from 0.15 mb to 15.4 Mb.This includes 26 cases of related syndrome of 28 cases and 8 cases of micro-repetition,current database and literature reported.ANgelman / Prader-Willi syndrome,4 cases of Williams-Beuren syndrome,2 cases of 15Q13.3 micro-missing syndrome,2 cases of XQ28(MECP2)micro-repetition syndrome,Kleefstra syndrome(9Q34.3 micro-missing syndrome 2 cases,Crit called syndrome,XP11.22 repetition syndrome,1P36 micro-missing syndrome,2Q33.1 lack syndrome,congenital RETT syndrome,MOWAT-WILSON SYNDROME,Jububet Comprehensive Joubert Syndrome,Phelan Mc Dermid syndrome(22Q13 lack syndrome),1 case of 10p15.3micro-missing syndrome.The positive rate was 24.2%.Among the 36 cases of patients with pathogenic CNV,13 males,17 females,13 cases with pre-pre-developing deformities and special faces,accounting for 36.1%(13/36),with lone symptoms(Autistic Spectrum Disorder)ASD)There were 4 cases,accounting for 11.1%(4/36)neurodametic inspection,with 19 cases,accounting for 52.7%(19/36),EEG examination tips to abnormally 4 cases,accounting for 11.1%(4/36).There were 48 cases of clinical significance,accounting for 32.2%,and 6 cases that may be pathogenic CNV.There may be 8 cases of benign CNV,and 28 CMA decisions are benign CNV,and 23 CMA test results suggest that there is no abnormality within detection.The result is negative.126 cases were detected by CMA containing copy number variation,and it was divided into two groups of children with epileptic disorders and patients with epilepsy.The two groups of pathogenic CNV detection rates were compared,and the difference was statistically significant,(p)<0.05).Conclusion The study found that the chromosome copy number variation exists in most of the ID / DD children,through genetic detection technology,we found and interpreted the clinical significance of the corresponding copy number,providing a lot of useful information for clinical diagnosis and treatment.24.2% of children had clinical chromosome copy number variation.The detection of the mutation of chromosome is very important to pediatric clinical genetics research.Studies have shown that the CMA can efficiently detect whether the chromosome copy number copies have micro-repetitive or slight deficiency.It is used for patients with patients with Id / DD for clinical notice to effectively improve the detection rate of pathogenic factors,reducing diagnosis.Economic cost,better understanding of the cause.CMA has a very clinical practicability in genetic diagnosis of children with ID / DD.For children ID / DD,CMA can be detected as a diagnostic test of genetic sickness.