For everyone with a glucose meter, monitoring diabetes is quick and simple process. Within a few seconds after daubing a miniscule amount of blood on a test strip, the concentration of sugar in your blood pops up on the meter’s screen. The glucose meter is so small and lightweight that it can be carried to and from work, out to dinner, on vacation–or around the world.
Now imagine that instead of testing with a glucose meter, you had to go to a hospital or clinic every time you needed to test your blood sugar. You couldn’t travel from your hometown unless you were sure there was a medical facility near and en route your destination.
People with Maple Syrup Urine Disease or MSUD (named for the sweet odor it causes in patients’ urine and ear wax) are forced to live a restricted lifestyle similar to the one I just described. MSUD is an inherited disease that prevents the body from reacting properly to the proteins valine, leucine, and isoleucine. These three branched-chain amino acids are acquired through diet, rather than produced internally, but are essential to the body’s growth and functionality. Because of a mutation in certain enzymes, people with MSUD are unable to break down valine, leucine, and isoleucine, leading to a dangerously high buildup of those amino acids in their systems. If MSUD goes untreated, it can lead to lethargy, lack of growth, seizures, mental impairment, and death.
Managing MSUD is a delicate act. People with the disease have to avoid eating too much of the branched-chained amino acids; at the same time, they need to consume enough of them for their bodies and minds to develop healthily. The concentration of the branched-chain amino acids also needs to be measured frequently, and the fact that there is no quick way to do so doesn’t make life for people with MSUD any easier. As a diabetic, I would have no trouble testing my blood sugar twenty times a day (if for some reason I wanted to). By contrast, every test for a person with MSUD involves a time-consuming visit to the hospital.
A friend of mine works in a clinic that treats children with MSUD. Once, as he saw me test my blood sugar, he was stuck by a thought. Could the technology used to power the glucose meter also be used to create a lightweight, portable meter to measure the levels of valine, leucine, and isoleucine in people with MSUD?
After thinking it over, this is the conclusion he reached: A meter would need to use enzymes to break down each branched-chain amino acid. The only enzyme of which my friend is aware that would react with one of the amino acids would also react with the other two. This means that it could only be used to measure the total level of the branched-chain amino acids–not a very helpful piece of information, as it’s essential for people with MSUD to see the concentrations of each amino acid separately. Before an effective meter for people with MSUD could be produced, researchers would need to identify three different enzymes that would react individually with valine, leucine, and isoleucine.
Still, creating a portable meter for people with MSUD is theoretically possible. The chances of someone actually doing so boils down to a practicality: funding. Since more than half of the people in the United States have diabetes, pharmaceutical companies have a clear incentive to fund research for cutting-edge diabetes products. MSUD, however, only affects one person in 180,000. With such a low statistic, it seems unlikely that much money will go towards developing a meter for people with MSUD any time soon.
Still, in the future….who knows? Maybe one day the glucose meter will become the model for a tool to help people with a disease other than diabetes.
