Comprehensive molecular phenotypic effects of the large deletion on chromosome 22q11.2

Purpose: 22q11 Deletion Syndrome (22q11DS) is a disorder caused by a heterozygous deletion of 3 million base pairs containing approximately 50 known genes on chromosome 22q. It occurs in around 1 in 4,000 live births. The common phenotypes of 22q11DS include a large spectrum of congenital anomalies, most notably of the cardiovascular system as well as several developmental neuropsychiatric disorders, in particular schizophrenia and autism spectrum disorders.Here we are testing the hypothesis that, in addition to changing the gene dosage of genes located within the CNV boundaries, large CNVs may have an effect on long-range chromosome interactions and epigenetic profiles. Methods: We generated Hi-C contact maps for 11 human lymphoblastoid cell lines and performed RNA-Seq on 14 cell lines and ChIP-seq of H3K27ac, H3K27me3 and CTCF for some of the cell lines. Results: We found dosage effects of 22q11del on chromosome contacts, epigenetic profiles and gene expressions. Extensive changes on these levels caused by 22q11del are global instead of confined to the deletion region only. Conclusions: Our results shed light on the comprehensive effects of 22q11del on different molecular levels in lymphoblastoid cell lines. Overall design: Hi-C data of 6 control and 5 22q11DS cell lines were generated. RNA-seq were performed for 9 control and 5 22q11DS cell lines. ChIP-seq of H3K27ac, H3K27me3 and CTCF were performed for 2 or 3 controls and 3 22q11DS cell lines. All the sequencing was performed using Illumina HiSeq.