Abstract: Objective
Chromosome microarray chip analysis technology is used to detect copy number variations(CNVs) in 150 children with psychomotor retardation of unknown causes, and to investigate the genetic causes.
Methods
The Affymetrix Cytoscan 750K chip was used for genomic analysis in 150 children with psychomotor retardation who were treated from January 2015 to June 2019 in our department.
Results
CNVs- related to MR/DD was detected in 25 cases, with a detection rate of 16.7%. Among them, 10 were known syndromes, 2 were microdeletions, 1 was large fragment deletions, 7 were clinically pathogenic copy number changes, and 5 were clinically unknown.
Conclusion
Chromosome microarray chip analysis technology can increase the level of molecular etiology diagnosis in children with psychomotor retardation of unknown causes, and is of great significance to further study of pathogenetic mechanism, which provides guidance for evaluating prognosis and family recurrence risk as well as making rehabilitation decisions.

Key words: Psychomotor retardation, Chromosomal abnormalities, Chromosome microarray chip analysis technology, Children