Why does one person wake up several times during the night while others can sleep straight through? Part of the answer is hidden in our DNA. Researchers at Radboudumc have discovered that specific segments of our DNA, so‑called FOXP genes, play an important role in regulating our sleep integrity. This finding emerged from their research into sleep problems in children with the rare FOXP1 syndrome.
Our bodies consist of billions of cells, all of which contain DNA: the genetic material that can be seen as the body’s instruction manual. DNA is made up of genes, small segments that contain instructions specifying what each cell should do. One of these genes is the FOXP1 gene.
Some children are born with a mutation in this gene. They have FOXP1 syndrome, a rare condition with only around fifty known patients in the Netherlands. Children with this syndrome often have developmental delays, particularly in learning and cognitive abilities, as well as in language and speech.
Sleep problems
However, parents noticed something else as well: their children sleep remarkably poorly. This, in turn, has a negative impact on learning and thinking, as well as on quality of life for both the children themselves and their families. ‘That’s why we wanted to understand where these sleep problems come from and whether they truly are part of the syndrome,’ says researcher Mireia Coll‑Tané.
When the researchers examined the sleep of children with FOXP1 syndrome, they observed the same pattern. Most children woke up several times during the night, had difficulty falling back asleep, and were often awake before five o’clock in the morning.
Fruit flies
To understand the origin of these sleep problems, the researchers turned to an unexpected model: fruit flies. At first glance, these tiny insects seem very different from humans, yet they share a surprising degree of similarity with us. In fact, fruit flies share about 75% of their genes with humans.
The researchers introduced the same DNA mutation found in FOXP1 syndrome into the fruit flies. The result was striking: the flies also slept for shorter periods and woke up more frequently. ‘That’s important’, says Mireia. ‘Because we observed the same effect, we now know that FOXP genes play a role in regulating sleep.’
Researcher Mireia Coll-Tané with her fruit flies.
Brain development
The researchers then took a closer look at the brains of the fruit flies to see what was happening at the cellular level. They discovered that FOXP genes are particularly important in specific nerve cells that help control different aspects of sleep. When there is a mutation in the gene, these nerve cells lose their ability to safeguard healthy sleep. Moreover, FOXP genes appear to be especially important during early brain development. ‘This means that early disruptions already affect how the sleep rhythm develops later in life,’ Mireia explains.
New treatments
Although FOXP1 syndrome is rare, sleep problems certainly are not. ‘Sleep problems occur strikingly often in rare genetic disorders, yet they still receive relatively little attention in research,’ says Professor Annette Schenck. ‘Our study shows that we can accurately model these sleep problems in fruit flies, which helps us better understand their underlying causes.’
These insights now allow to test and develop new treatments. Annette adds: ‘Ultimately, our work aims to contribute to a better quality of life for children with rare genetic disorders in which sleep is a major problem.’
About the publication
This research was published in The Journal of Clinical Investigation: Conserved sleep disturbances in FOXP1 syndrome originate from developmental dysregulation of peptidergic signaling. Mireia Coll-Tané, Ilse Eidhof, Jie Han, […] Saskia Koene, Anna Castells-Nobau, Annette Schenck. DOI: 10.1172/JCI193475.
-
Want to know more about these subjects? Click on the buttons below for more news.
