GSE98477
YY1 haploinsufficiency causes an intellectual disability syndrome featuring transcriptional and chromatin dysfunction [ChIP-seq]
Yin and yang 1 (YY1) is a well-known zinc-finger transcription factor with crucial roles in normal development and malignancy. YY1 acts both as a repressor and an activator of gene expression. We have identified 23 individuals with de novo mutations or deletions of YY1 and phenotypic features that define a syndrome of cognitive impairment, behavioral alterations, intrauterine growth retardation, feeding problems, and various congenital malformations. Our combined clinical and molecular data define the 'YY1 syndrome' as a haploinsufficiency syndrome. Through immunoprecipitation of YY1-bound chromatin from person-derived cells, using antibodies recognizing both ends of the protein, we show that YY1 deletions and missense mutations lead to a global loss of YY1 binding, with a preferential retention at high-occupancy sites. Finally, we uncover a widespread loss of H3K27 acetylation in particular on the YY1-bound enhancers, underscoring a crucial role for YY1 in enhancer regulation. Collectively, these results define a clinical syndrome caused by haploinsufficiency of YY1 through dysregulation of key transcriptional regulators. Overall design: Individuals with mutations or deletion in YY1 were identified among patients with idiopathic intellectual disability. LCLs were established from 4 of these patients (1 deletion, 2 missense mutations, and 1 non-sense mutation undergoing non-sense-mediated decay) and from unrelated controls. These lines were profiled for genome-wide YY1 occupancy using two antibodies respectively binding each end of the protein, as well as for H3K27ac and H3K27me3.