Expression Patterns of Escape Genes in Turner Syndrome Fibroblasts and Induced Pluripotent Stem Cells

Turner syndrome (TS) is an X monosomy-related disorder caused by X chromosome nondisjunction during embryonic development. Patients with TS have only one intact X chromosome, with the other either completely or partially lost. TS affects various tissues, including the liver, kidneys, brain, cardiovascular system, and ovaries. These abnormalities are suggested to involve an altered dosage of escape genes that evade X chromosome inactivation. However, the mechanisms and roles of these escape genes in the TS phenotype remain unclear. We hypothesized that the expression levels of escape genes differ between wild-type (WT) and TS cell lines. In this study, we generated induced pluripotent stem cell (iPSC) lines from WT and TS fibroblasts and examined the expression levels of escape genes in both undifferentiated fibroblasts and reprogrammed iPSCs from WT and TS samples. The reprogrammed WT and TS iPSCs exhibited general characteristics of pluripotency, including the expression of pluripotency markers and the potential to differentiate into all three germ layers. Forty-five escape genes were differentially expressed between the WT and TS cell lines. Among these, five genes (ATP7A, PHKA1, EBP, ZFX, and SMC1A) were suggested to be implicated in the TS phenotype. However, further studies using additional cell lines are necessary to clarify the correlation between TS and escape genes.