Biochemistry of MSUD

MSUD is the deficiency in branched-chain alpha-keto acid dehydrogenase(BCKDH). BCKDH is involved in catabolism of 3 specific amino acids - Valine, Leucine, Isoleucine.
 


These 3 amino acids are branched-chain amino acids(BCAA) and for their metabolic pathways, the last step where FAD is used to become FADH2. The initial few steps proceed as normal - formation of alpha-keto acids to branched-chain carboxylic acids.

Therefore, the resultant products are the accumulation of these BCAA and their corresponding alpha-keto compounds that they form.


References :

The Medical Biochemistry Page, 2014. Introduction to Maple Syrup Urine Disease : MSUD [Online]
Available at : <http://themedicalbiochemistrypage.org/msud.php>

UIC, 2014. Biochemical Background [Online]
Available at : <https://www.uic.edu/classes/phar/phar332/Clinical_Cases/aa%20metab%20cases/MSUD/MSUD%20biochem%20background.htm>

UT South Western, 2014. Maple Syrup Urine Disease (Branched-Chain Ketoaciduria) [Online]
Available at : <http://www4.utsouthwestern.edu/chuang_lab/MSUD.html>