Génétique des rythmes circadiens et des troubles du rythme circadien du sommeil

The complexity of circadian regulation, in addition to the many environmental influences, involves genetic predisposing factors. These factors begin to be discovered. Over the past few years, a revolution in the understanding of the molecular basis of circadian rhythm generation has led to the identification of a number of core clock genes, and the development of feedback models that explain how these core components interact to generate a circadian rhythm. Recent progress in molecular genetics and the development of detailed human genomic map have already led to the identification of genetic factors contributing to the pathophysiology of circadian rhythm sleep disorders. At least eight human orthologs of mouse core clock genes have been identified, and a mutation in hPER2 is responsible for the autosomal-dominant familial advanced-sleep-phase syndrome in humans. However, single gene disorders are rare and most common disorders are complex in terms of their genetic susceptibility environmental factors, gene-gene and gene-environment interactions.