A European study, done by LMU researchers, has shown that a gene may influence how long humans stay asleep at night. The gene is called ABCC9, and it is also a genetic factor in heart disease and diabetes. The researchers scanned genomes for variations in sleeping patterns. In this recent study however, more than 4000 people from European populations filled out questionnaires to describe their sleeping habits. It revealed that individuals who had two copies of one of the ABCC9 genes slept for a shorter period of time than those with copies of another version. Apparently the ABCC9 gene codes for the protein SUR2, which helps regulate the potassium channel in the cell membrane. The channel then acts as a sensor of metabolism in energy expenses. When further researchers blocked the ABCC9 gene in the fruit fly nervous system, the subjects' sleep cycle was shortened.
(Many variables also determine sleep duration such as age, sex, and daily activities.)