Maple Syrup Urine Disease

Maple Syrup Urine Disease (MSUD) is an inherited metabolic disorder in which the body cannot properly break down certain amino acids—specifically leucine, isoleucine, and valine, collectively called branched-chain amino acids (BCAAs). The name comes from the distinctive sweet, maple syrup-like odor of the urine, sweat, and earwax in affected individuals.

Without proper breakdown, BCAAs and their toxic byproducts accumulate in the blood and tissues, causing damage to the brain and nervous system. The classic, most severe form presents in newborns within the first few days of life with poor feeding, vomiting, lethargy, and a distinctive odor. Without treatment, it progresses rapidly to seizures, coma, and death.

There are several forms of MSUD with varying severity. The classic form is the most severe and most common. Intermediate, intermittent, and thiamine-responsive forms are milder, with symptoms appearing later or only during metabolic stress such as illness. Even in milder forms, metabolic crises can occur during infections or other stresses and require emergency treatment.

MSUD type 1B is caused by mutations in the BCKDHB gene, which encodes part of the enzyme complex needed to break down BCAAs. The condition is inherited in an autosomal recessive pattern and is more common in certain populations, including the Old Order Mennonite community. Treatment involves a lifelong diet strictly limited in BCAAs, with regular monitoring. Liver transplantation can be curative.

NutraHacker examines the following gene related to Maple Syrup Urine Disease:

• BCKDHB

For more information about your own genetic profile as related to Maple Syrup Urine Disease, please check out our NutraHacker Carrier Status and Drug Response Report.

Or to get going without any further delay, upload raw DNA data and find out more about your carrier status today.