What is Maple Syrup Urine Disease?

Article Details
  • Written By: P.S. Jones
  • Edited By: Andrew Jones
  • Last Modified Date: 01 October 2019
  • Copyright Protected:
    Conjecture Corporation
  • Print this Article
Free Widgets for your Site/Blog
In 2008, Mike Merrill became the first publicly traded person, allowing shareholders to control his life decisions.  more...

October 23 ,  1983 :  Suicide bombers killed nearly 300 US and French military troops in Beirut.  more...

Maple syrup urine disease (MSUD) is a genetic disorder that prevents the body from processing amino acids properly. Amino acids are considered the building blocks of proteins, and are essential to life functions. This disease can kill newborn babies within months, if not treated properly with a lifelong restrictive diet. With consistent treatment, the child will live a long and relatively healthy life.

Maple syrup urine disease is so named because it is often characterized by a sweet smell similar to maple syrup in its victims’ urine. MSUD is also called branched-chain ketoaciduria, because it is the branched-chain alpha-ketoacid dehydrogenase complex (BCKDH) that is missing from the suffers' bodies. This is what causes the buildup of branched-chain amino acids as well as their toxic byproducts in their blood and urine.

This is an inherited disorder, and thus it is present at birth. It is also a recessive disorder, meaning that the disease may be present in a child’s genetic makeup without the disease being present. Recessive genes must be present in both parents genetic makeup to be passed on. This makes the quite rare. It is possible for both parents to not have this disease, yet still pass on the trait to their child. The only way to prevent MSUD is through genetic counseling before conceiving a child.


MSUD is a very rare disorder, usually diagnosed in infancy. The disease is characterized by poor feeding and excessive vomiting, as well as the telltale odor in the infants’ urine. Those who have the disease also are uncharacteristically lethargic and experience developmental delays. Victims may also experience seizures, comas, and neurological damage as the disease progresses, especially if the required diet is not properly followed.

Some states require that all newborns be tested for maple syrup urine disease at birth. In other states, testing is not done unless specific symptoms are observed. Simple testing can be done with a blood test. The amount of branched-chain amino acids in the blood sample are measured to determine if further genetic testing is needed. Genetic testing is much more in-depth can be done by mapping the child’s DNA to determine if he or she carries two recessive genes.

The main treatment for maple syrup urine disease is through diet. The child’s diet should contain limited leucine, isoleucine and valine, because these are the branch-chain amino acids that the child will not be able to process. Still, the diet must be nutritionally balanced. Proteins are necessary for growth, development and general good health. Those who suffer from maple syrup urine disease must use protein supplements to maintain a healthy lifestyle, and often consult with dietitians regularly.


You might also Like


Discuss this Article

Post 4

There was a boy who had this at my middle school. I remember looking it up in the Encyclopedia Britannica in the public library and also in a medical dictionary. I was a weird kid.

Seems like he had some developmental delays and I know he always brought his lunch because he said he couldn't eat in the cafeteria because they didn't fix foods he could have. We were rather all of that opinion of the cafeteria food, but I digress.

This was the only person I've ever known or heard of who had this disorder. He only spent one year at my school. I've often wondered what happened to him, and if he's even still alive.

Post 3

I've never known anyone with this disease, although my mom said one child was in the hospital with it where she worked in the fifties.

She said the child was on a limited diet because even then, they knew the diet was crucial to the child's survival.

Mom was a lab tech and said the doctor was somewhat skeptical about the child's life expectancy. She said she didn't know what happened to the child after her time in the hospital.

At that time, no one was sure what caused this disease, and no one had ever seen it. She said the child was diagnosed at the Mayo Clinic.

Post your comments

Post Anonymously


forgot password?