What Is Bardet-Biedl Syndrome?
Inspired by one family’s tireless efforts to help their daughter, Ask Science discusses the complex causes of Bardet-Biedl Syndrome, or BBS. Read on for the chance to be a part of the solution!
Lee Falin, PhD
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What Is Bardet-Biedl Syndrome?
I want to introduce you to a young lady named Lucy Pothier. Lucy has a condition known as Bardet-Biedl Syndrome, or BBS. This syndrome causes vision-loss, 
obesity, and a variety of other health issues in children. The I Love Lucy Project is a fund-raising effort started by Lucy’s family in 2009 to help fund BBS research..
Let’s take a look at what we know and don’t know about BBS, and just what makes it such a complicated syndrome to treat.
Cilia Acting Silly
Understanding BBS requires that we first take a little tour of the outside of our cells. In the early days of science, people staring at cells through microscopes noticed that they had these wavy hair-like things sticking out of them. These little wavy hairs were named cilia, which is the Latin word for eyelashes.
Scientists quickly realized that the cilia were involved in all kinds of important things, such as moving eggs down fallopian tubes and pushing germs and mucus out of the lungs. Single-celled organisms also use cilia to propel themselves around in liquid.
Then in 1898, someone noticed that amongst all of these wavy little cilia, there was always a single cilium that acted differently. Most of the time it just sort of sat there, ignoring its wavy cousins. Since scientists love to categorize things, they started referring to the normal, wavy cilia as motile cilia (meaning “cilia that move”), and the lone non-moving cilium they dubbed immotile.
They assumed that this lone cilium must be a vestigial leftover of evolution, much like the appendix; not really needed any longer, but still hanging out like an unwelcome party guest. Satisfied with this conclusion, they proceeded to ignore immotile cilia (or primary cilia as they were later named), for the next 100 years or so.
Then in the late 1990’s, scientists started to realize that there was more to these primary cilia than they originally thought. It turns out that they have a variety of important functions, such as acting like little antennae to let the cell know what’s going on outside of the cellular membrane, detecting all kinds of things like light intensity, gravity, temperature, and the concentration of various chemicals. In the eye they serve as transporters, sending molecules from one end of the photoreceptor cell to the other.
Super-Complex Nanomachines
As you might guess from their diverse capabilities, the internal workings of primary cilia are extremely complicated. Our current understanding of how they work involves over 600 different proteins working both independently and in groups. As you might imagine, with such a complicated setup, there are several things that can go wrong with primary cilia. The conditions caused by something going wrong with primary cilia are referred to as ciliopathies. They include various kidney and liver diseases, and BBS.
One of the things that makes BBS and other ciliopathic conditions so complicated to research is that so many different genes appear to be involved. The symptoms of BBS in particular appear to be caused by a group of genes called “BBS genes.” Over a dozen different BBS genes have been identified, and their primary role appears to be to encode the proteins, which help form the basal body, or base of the primary cilia.
To make things even more complicated, several other groups of genes have been discovered which help the BBS genes do their job, as well as helping to keep the cilia functioning normally after they are formed.
So two different people could have mutations, or changes in one or more of any of these genes which could lead to BBS. Complicating things further is that not everyone with BBS presents with the same set of conditions. Some people might not have obesity, or have it less than others. Still other people might be born with an extra finger or toe, while others show no symptoms until adulthood.
While some of this variation in symptoms can be explained by genetics, most of the cause is still a mystery. The most likely explanation is epigenetic variations to the genome, which are chemical changes to the genome which can occur independently of the genetic sequence. Some of these changes are inherited from your parents, while others can be affected by your lifestyle or environment. (Learn more details on epigenetics here).
One Registry to Rule Them All
This extreme variation in symptoms, genetics, and epigenetics related to BBS is exactly why the I Love Lucy project is raising money to start a BBS registry. A registry provides a central database of patient information related to a particular condition. By storing all of this information in one place, scientists and doctors can start looking for patterns in the data that will help them unlock the secrets of BBS, hopefully leading them to more effective treatments and therapies.
Conclusion
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So now that you know more about Bardet-Biedl Syndrome, if you’d like to help out, head over to The I Love Lucy Project to find out more. If giving money isn’t your thing, you can check out some of the other offers associated with the fundraiser, which allow you to get something cool while still helping out.
Speaking of cool, my new middle-grade science fiction novel, Half Worlder, is now available for sale on Amazon for just $2.99. And, throughout the month of December, half of the proceeds go toward the I Love Lucy project.
So pick up a copy of Half Worlder for the sci fi fan on your holiday list today! And once you’ve had a chance to read it, I’d love it if you could post your candid review on Amazon.
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