Chromatin organisation and human disease

Targeted alterations in the nucleoprotein fibre of chromatin represent a major mechanism of gene control in eukarya, and the aetiology of a large number of human pathological conditions has been traced to molecular lesions in various components of chromatin-based gene regulatory pathways. In this review, those aspects of chromatin structure that are most immediately relevant to transcriptional control are briefly described, highlighting the various types of chromatin structure modification and disruption that occur in vivo and describing, in some detail, the biochemical and functional properties of the various molecular machines that effect such modification and disruption. In addition, a synthetic scenario for their involvement in the sequence of events that take place during gene repression and activation in vivo will be provided. After a description of the major clinical features and underlying molecular lesions in a number of human disorders with a known ‘chromatin-based’ aetiology, including various malignancies, as well as endocrinological and inherited conditions, this review will discuss currently available pharmacological agents that interfere with gene control pathways, describing the present state of their use in clinical settings and concluding with a perspective on their future promise in the therapy of human disease.