Maple Syrup Urine Disease (MSUD) is an inherited disorder where the body cannot properly process certain amino acids. It gets its name from the sweet smell of the urine of affected infants. It is caused by a defective protein complex that leads to a buildup of toxic levels of certain amino acids in the body. MSUD affects around 1 in 185,000 infants worldwide but is more common in some populations. It requires a special diet and frequent testing to manage and prevent serious complications like seizures or coma.

1. Maple Syrup Urine
Disease
Branched-chain Ketoaciduria
By Bobby Mattes

2. How it got it’s name
The reason why it got its
name is !om the sweet
odor it gives off !om the
Urine.

3. What is it ?
It is a inherited disorder in which you could not process
amino acids properly. It gives mostly infants in the
beginning of infancy the sweet sme%ing odor.

4. What happens in the body
The reason for the
build up is because of
a defective BCKD
protein complex so
large toxic amounts
of leucine, isoleucine
and valine build up
in the body.

5. How common is it
It effects an estimated 1 in 185,000 infants Worldwide. It
is Much more !equently found in old order mennonite
populations with an estimated 1 in 380 newborns.

6. Management
To keep it under control it requires careful monitoring of
blood chemistry and a special diet and !equent testing.
If not treated it can lead to seizures, coma and death.

7. What genes are involved
Mutations in BCKDHA, BCKDHB, DBT and DLD
cause the Disease. And their job as being Genes is to give
instruction to make proteins that work together as a
complex.

8. How do people inherit it
It is a autosomal Recessive so it needs two copies but one
of the parents could be a carrier but not now it.

9. Citations
"Maple Syrup Urine Disease." Wikipedia. Wikimedia Foundation, 28 Mar. 2012. Web. 04 Apr. 2012. <http://
en.wikipedia.org/wiki/Maple_syrup_urine_disease>.
"Maple Syrup Urine Disease." - Genetics Home Reference. Web. 04 Apr. 2012. <http://ghr.nlm.nih.gov/condition/maple-
syrup-urine-disease>.