Chromosome engineering to correct a complex rearrangement on Chromosome 8 reveals the effects of 8p syndrome on gene expression and neural differentiation

Chromosomal rearrangements on the short arm of chromosome 8 cause 8p syndrome, a rare developmentaldisorder characterized by neurodevelopmental delays, epilepsy, and cardiacabnormalities.While significantprogress has been made in managing the symptoms of 8p syndrome and otherconditionscaused by large-scalechromosomalaneuploidies, no therapeutic approach has yet been demonstrated to target the underlyingdisease-causingchromosome.Here, we establish a two-step approachto eliminate theabnormalcopy ofchromosome 8and restore euploidy in cells derived from an individual with a complex rearrangement ofchromosome 8p.Transcriptomic analysis revealed 361 differentially expressed genes between the proband andthe euploid revertant, highlighting genes both within and outside the 8p region that may contribute to 8psyndrome pathology. Our work demonstrates the feasibilityof using chromosome engineering to correct complexaneuploidies invitro and suggests a potential therapeutic avenue for disorders caused by chromosomalrearrangements.