Extra Credit for BIOC 460 Final

1. Case Study
By: Shelby Thorvilson

2. The Patient & Their
Symptoms
Jacob, a new born baby, was healthy as can be a few
days after his birth. However, after that he started
showing characteristics of seizures, irritability, failure to
thrive, poor suckling response, and little interest in
feeding. The doctors performed an examination that
showed no sign of infection and his X-rays came back
normal. His parents notice a sweet smell to Jacob’s
urine, and become concerned because his symptoms
are eerily similar to those of an older brother that died
shortly after birth. The doctors decide that additional
testing should be done.

3. What is your initial diagnosis for this
patient?
What additional tests would you run to
confirm your hypothesis?

4. Additional Testing
• Urine Analysis
• Blood Analysis
• White Blood Cell Analysis
• Tandem Mass Spectrometry
• Molecular Testing (prenatal)
• Amino Acid Concentrations in Amniotic Fluid
(prenatal)

5. Diagnosis
• Maple Syrup Urine
Disease
• MSUD is an inherited
disorder characterized by
the deficiency of
branched-chain alpha-keto
acid dehydrogenase
complex, an enzyme
required to breakdown
specific amino acids in the
body
• Since these amino acids
are not metabolized, they
along with various
byproducts, abnormally
accumulate in the cells
and fluids of the body

6. Maple Syrup Urine
Disease
• MSUD is caused by a deficiency of the
BCKD complex. This catalyzes the
decarboxylation of the alpha-keto
acids of leucine, isoleucine, and valine
to their respective branched-chain
acyl-CoAs
• Decarbozylation of the alpha-keto
acids is the second step in the
degradation pathway of
• The BCKD complex has three different
catalytic components (E1, E2, E3)
• Mutations in E1, E2, and E3 cause
MSUD

7. Treatment Options
• Protein-free diet
• Intravenous administration
of amino acids that don’t
contain branched-chain
amino acids, combined
with glucose for extra
calories
• Infants have a diet of
formula with low levels of
the amino acids leucine,
isoleucine, and valine.

8. References
Maple Syrup Urine Disease - NORD (National
Organization for Rare Disorders). (n.d.). Retrieved
December 16, 2016, from https://rarediseases.org/rare-
diseases/maple-syrup-urine-disease/
Maple syrup urine disease: MedlinePlus MedicalEncyclopedia.
(n.d.). Retrieved December 16, 2016, from
https://medlineplus.gov/ency/article/000373.htm
Maple Syrup Urine Disease. (n.d.). Retrieved December 16,
2016, from http://emedicine.medscape.com/article/946234-
overview