X Chromosome Inactivation mechanisms. Clinical implications and consequences

X-chromosome inactivation (XCI) is the process that allows gene dose compensation between males and females in numerous species and one of the basic genetic mechanisms for life. Currently, the role of genetics in clinical practice is growing exponentially, with the ICX process being increasingly present in research in this field. Recent studies on X-chromosome inactivation in humans relate this process to much more pathology than it was initially thought. Some examples of this pathology such as cancer, X-linked diseases or the increasingly diagnosed autoimmune diseases are just some of the lines of research that bring the ICX process closer to clinical practice. This paper attempts to summarize the main mechanisms that govern the ICX process, as well as to review the relevance of this process in certain diseases and to synthesize some of the possible future research lines on this topic.