[Genetic Analysis of a Case of Mosaic Trisomy 21 Associated with Autism Spectrum Disorder].

Objective To explore the genetic basis for a child with autism spectrum disorder (ASD) and congenital heart disease.Methods G-banded chromosomal karyotyping was carried out for the patient and his parents.The child was also subjected to whole exome sequencing (WES) and low-coverage massively parallel copy number variation sequencing (CNV-seq).The result was validated by chromosomal microarray analysis (CMA).Results The karyotype of the patient and his parents were normal.No significant genetic variation was found by WES.However,CNV-seq has discovered a 47,XY,+21[10 ％]/46,XY[90％] mosaicism in the patient.The result was confirmed by CMA.Conclusion In addition to Down syndrome,low proportion mosaic trisomy 21 is also associated with ASD.WES and CNV-seq can enable accurate diagnosis for patient with unexplained ASD.