Maple Syrup Urine Disease
(Diseases)
This page will help you find answers to your questions about Maple Syrup Urine Disease (MSUD).
What is Maple Syrup Urine Disease (MSUD)?
It is a rare genetic disorder that occurs when the body cannot break down certain amino acids (the building blocks of protein). This leads to the accumulation of harmful substances in the blood and urine.
- Normally, the body breaks down proteins in foods such as meat and fish into amino acids, and excess amino acids are removed. However, children with MSUD cannot break down three specific amino acids: leucine, isoleucine, and valine. The buildup of these amino acids causes serious harm.
- One of the most distinctive symptoms of this disease is urine that smells like maple syrup, which is how the condition got its name.
- What are the symptoms of MSUD?
Symptoms of MSUD usually appear during the first few days or weeks after birth, and the most common symptoms include:
- Sweet-smelling urine and sweat.
- Poor feeding or loss of appetite.
- Weight loss.
- Children with MSUD may also experience episodes called metabolic crises, sometimes early in life. Symptoms of a metabolic crisis include:
Low energy.
Vomiting.
Irritability or restlessness.
Breathing difficulties.
It is important to seek medical help immediately if your child shows signs of a metabolic crisis. Your doctor can guide you in recognizing these warning signs.
- What causes MSUD?
- MSUD is inherited genetically. Children with the disorder inherit a gene mutation that prevents their bodies from breaking down the amino acids leucine, isoleucine, and valine.
Normal genes contain instructions that tell the body how to make the enzymes responsible for breaking down these amino acids. However, when a child inherits a gene mutation, the body may:
Not produce the enzyme at all.
- Produce an insufficient amount.
Produce enough enzymes, but they do not function properly to break down amino acids.
As a result, these amino acids accumulate and become toxic to the body.
How is MSUD diagnosed?
- Most infants with MSUD are identified through newborn screening programs, followed by additional diagnostic tests, which may include:
Blood and urine tests.
Specialized measurements to detect the levels of the three amino acids (leucine, isoleucine, and valine) in the blood.
If there is a family history of MSUD, prenatal testing can be performed through chorionic villus sampling (CVS) for early detection, allowing doctors to plan necessary early interventions as needed.
- How is MSUD treated?
- Dietary management:
- Breast milk naturally contains amino acids that need to be restricted in MSUD. Therefore, it is essential to prescribe a special medical formula containing all the necessary vitamins, minerals, and other amino acids the baby needs.
Infants with MSUD are referred to a nutrition specialist to establish a low-protein diet plan and provide detailed guidance to parents. The goal is to limit the intake of certain amino acids to prevent the child consumes.
Patients with MSUD must follow a low-protein diet for life. As the child grows, they will need to learn how to manage their diet independently and maintain regular contact with their dietitian for ongoing monitoring and advice.
Liver transplant:
- A liver transplant is considered a final treatment option for MSUD. While a successful transplant allows the patient to follow a normal diet, it is a major procedure with its own risks. After transplantation, the patient must take immunosuppressive medication for life to prevent organ rejection.
- Therefore, it is essential to carefully weigh the benefits and risks before deciding whether to undergo a liver transplant.
- How can MSUD be prevented?
- MSUD cannot be prevented because it is a genetic disorder, but the risk of having an affected child can be reduced through genetic counseling and testing.
- For a child to have MSUD, two copies of the defective gene—one from each parent—must be inherited.
- If both parents carry the mutation, the child has:
- 25% chance of having MSUD.
- 50% chance of being a carrier.
25% chance of being unaffected.
While MSUD cannot be completely prevented, it is vital to inform your midwife and doctor if there is a family history of the condition. This ensures that proper guidance and support for genetic health risks are provided.
What are the complications of MSUD?
If left undiagnosed or untreated, MSUD can lead to serious complications such as:
Acute pancreatitis.
Blindness.
Brain edemaBCKD(swelling).
Cerebral ischemia (reduced blood flow to the brain).
Intellectual disabilities.BCKD.
Muscle spasms.
Osteoporosis.
Seizures.
When should you see a doctor?
