Human genetics is the medical field with the most rapid and, one can say, overwhelming
progress. The medical practitioner constantly needs to be up-to-date on the newest developments
in his field. The diversity and rapid dynamics of advancements in genetics can sometimes
overcome the assimilation possibilities of one person; thus, overspecialization for narrowing
and deepening the research focus is needed. Consequently, expert opinion is much
valued. This book aims to provide exactly such opinions regarding several genetic diseases.
Physiology of Circadian Rhythmicity
The sleep-wake cycle is the most evident of the many 24-h rhythms in humans. Prominent daily variations also occur in endocrine, thermoregulatory, cardiac, pulmonary, renal, gastrointestinal, and neurobehavioral functions. At the molecular level, endogenous circadian rhythmicity is driven by self-sustaining transcriptional/translational feedback loops (Fig. 28-2). In evaluating a daily variation in humans, it is important to distinguish between those rhythmic components passively evoked by periodic environmental or behavioral changes (e.g.