What Is Maple Syrup Urine Disease?
Urine contains various substances, such as water, urea, uric acid, creatinine, salt, and other substances the body excreted. Urine has a distinctive odor. However, some babies' urine and sweat can smell like maple. Sweet, like burnt sugar. How come? Let's read more.
The sweet smell of urine actually indicates one of the symptoms of maple syrup urine disease, or MSUD. Symptoms usually appear 48 hours after birth or after the baby receives protein from their food. In children, symptoms develop before the age of 7 years.
MSUD is a rare disease. It happens in one in 185,000 births. This disease can affect both male and female babies. Although it is a rare disease, MSUD can be treated with a special diet.
Babies with MSUD usually show symptoms such as
- Smelly urine and sweat
- Reluctant to breastfeed, so weight loss
- Frequent vomiting
- Difficulty breathing
- Continuously sleepy and looking lethargic.
What is maple syrup urine disease?
MSUD is a rare congenital disease that affects babies' metabolism from birth. The cause is that the baby lacks the metabolic enzyme branched-chain α-keto acid dehydrogenase (BCKDH).
This disease prevents the body from breaking down certain amino acids, namely leucine, isoleucine, and valine, so it cannot convert food into energy to maintain body health.
These amino acids and their byproducts build up in the blood, damaging the brain and other organs.
There are four types of MSUD:
1. Classic
This is the most common and severe type of MSUD. In this type, there is little or no enzyme activity. Symptoms appear about three days after birth.
The baby seems lethargic and gradually develops abnormal movements or seizures, hypertonia, neurological symptoms, and a distinctive odor of maple syrup in the urine, sweat, and earwax.
Children with MSUD may also have intellectual disabilities, behavioral problems, or be prone to bone fractures.
2. Intermediate
Symptoms develop pretty slowly. Usually seen at the ages of 5 months to 7 years. These children typically have a poor appetite, so they appear lethargic and have poor growth.
They are not less active than other children their age. If the conditions worsen, they will have seizures, brain damage, coma, and life-threatening complications.
3. Intermittent
Children with intermittent MSUD have normal brain growth and development. Most people can even consume regular amounts of protein.
Symptoms of intermittent MSUD typically do not show until they are triggered by sickness or stress. Compared with people with classic MSUD, people with this type of maple syrup syndrome can often tolerate higher levels of amino acids in their urine and bloodstream.
4. Thiamine-responsive
This type of MSUD responds to treatment with high doses of vitamin B1 (thiamine) and a restricted diet. People with thiamine-responsive MSUD improve their tolerance to all three amino acids.
Intermediate, intermittent, thiamine-responsive MSUD can occur at any age. Sometimes MSUD symptoms only appear when sick or stressed. MSUD symptoms in older children include abdominal pain, vomiting, anorexia, weight loss, muscle weakness and loss of control, and slurred speech.
How is it treated?
In some hospitals, doctors routinely test babies. Classic MSUD is often diagnosed within hours of birth. Doctors can confirm the diagnosis using blood and urine tests.
Doctors can diagnose other types of MSUD by smelling the urine for the smell of maple syrup, evaluating other symptoms, and performing blood, urine, or genetic tests.
If not diagnosed and treated at birth, MSUD can be life-threatening, even within two weeks of birth. Therefore, babies must immediately undergo a low-protein diet with a unique formula free of the amino acids leucine, isoleucine, and valine.
Older children must maintain a low-protein diet throughout their lives. This includes avoiding high-protein foods like meat, fish, cheese, eggs, and nuts.
This diet limits the amount of amino acids received, especially leucine, isoleucine, and valine. These protein levels must be monitored throughout life to prevent amino acid buildup.
Doctors may use other medical treatments, such as IV drips or feeding tubes, if the symptoms are severe, to help deliver needed nutrition. Doctors may also use glucose or insulin infusions to help regulate the amount of amino acids in the blood or filter the blood entirely with a type of dialysis.
A liver transplant provides permanent treatment for MSUD. The liver produces the enzymes needed to break down amino acids and allows people with MSUD to live without symptoms or a restrictive diet.
Early treatment allows children to grow, develop, and have normal intellectual abilities.
Prevention
You can’t prevent MSUD. However, you can lower your risk of having a baby with MSUD by ensuring that neither you nor your spouse carries the MSUD gene mutation. The best way to prevent this is to choose a partner who doesn’t share your DNA.
If you have a sibling or other family with MSUD, consult your doctor before you get pregnant to discuss the risk of transferring the disease to your child. Your healthcare provider may test you and your spouse to check if you are carriers of the gene that causes MSUD.
