This story really hits home: It is about 4am my time--
I often wake around 3-4am when I'm on dayshifts, and
I like to go to bed fairly early--usually start thinking
about it around 8pm...though usually don't actually go
to bed til around 9. My father has a similar sleep
schedule...and my brother's sleep schedule is really
bizzare...
'Early to bed, early to rise' may be genetic, study shows
by Randolph E. Schmid
The Associated Press
WASHINGTON - A sleep syndrome that sends people early to bed and early to rise doesn't necessarily make them healthy, wealthy and wise. The disorder, traced to a single gene, can send sufferers to bed when everybody else is going strong, University of Utah researchers found.
Understanding what governs people's wake-sleep cycles has implications for dealing with insomnia, jet lag, shift work and depression, the scientists report in the September issue of the journal Nature Medicine.
Researchers studied people who have a shorter-than-normal wake-sleep cycle. Regardless of work schedules or social pressures, these folks just can't stay up much later than 8:30 p.m., and they tend to wake up around 5:30 a.m.
It's called "familial advanced sleep-phase syndrome" because it shifts the normal wake and sleep pattern forward.
Louis Ptacek and colleagues found 29 people in three families with the disorder.
The normal population contains plenty of "morning-lark" and "night-owl" people who function better at different times of day, but people with this syndrome are not simply morning people, Ptacek emphasized.
Most creatures seem to operate on a biological clock synchronized to a 24-hour day. This rhythm controls a variety of daily biochemical and behavioral cycles including fluctuations in sleep and wakefulness.
"This is a situation which is quite comparable to the changes that occur normally in aging humans," Ptacek said. "Most aged humans, starting around age 65 or 70, show these sorts of changes, reporting problems sleeping, usually marked by earlier onset to sleep . . . (and) frequent waking in the night. But this is a genetically linked trait, not simply aging, as it appears at an earlier age," Ptacek explained.
For people with this syndrome the cycle is shorter, and the constant conflict between their body clock and coping with the world leads to their shifted sleep-wake rhythm.
"These aren't diseases per se, and most people just live with this sleep pattern and never see a doctor about it," Ptacek said.
By studying family relationships, the scientists found that the disorder is inherited in a way common to other inherited traits caused by a single gene, such as eye color.
So now Ptacek's team is working to identify the specific gene responsible. Finding the gene could lead them to the protein it produces to cause the body's time shift - a discovery that could lead to developing drugs to treat not only the sleep disorder, but jet lag and other conditions.
But, said Ptacek, "we need to understand the normal biology first. Then we can work on altering the clock and helping people who fly or do shift work."
"Presumably, this protein is just one of the gears in the (body) clock. By studying one gear we can get a handle on the other gears around it, and we may get an insight about why they have this trait and how the normal clock functions," he said.
The search for the gene may be arduous.
"There are approximately 80,000 genes in human genome, this is a single one of those 80,000. Think of the genome as a library with 80,000 books, and we're looking for a spelling error in a single book," he said. |
