http://www.ncbi.nlm.nih.gov/disease/Signals.html
Signals Ataxia_telangiectasia Baldness Cockayne_syndrome Glaucoma SRY: sex determination Tuberous_sclerosis Waardenburg syndrome Werner_syndrome SIGNAL TRANSDUCTION within and between cells mean that they can communicate important information and act_upon it. Hormones released from their site of synthesis carry a message to their target site, as in the case of leptin, which is_released from adipose_tissue (fat_cells) and transported via the blood to the brain. Here, the leptin signals that enough has_been_eaten. Leptin binds to a receptor on the surface of hypothalamus cells, triggering subsequent intracellular signaling networks. Intracellular signaling defects account_for several diseases, including cancers, ataxia_telangiectasia and Cockayne_syndrome. Faulty DNA repair mechanisms are_invoked also in pathogenesis, since control of cell_division, DNA synthesis and DNA repair all are_linked inextricably. The end-result of many cell signals is to alter the expression of genes (transcription ) by acting on DNA-binding proteins. Some diseases are the result of a lack of or a mutation in these proteins, which stop them from binding DNA in the normal way . Since signaling networks impinge_on so_many aspects of normal function, it is not surprising that so_many diseases have at_least some basis in a signaling defect