Maple syrup disease (MSUD) is a condition in which the body fails to break down three proteins - leucine, isoleucine and valine. As a consequence, these proteins and the toxic products of their decomposition accumulate in the body, leading to its gradual poisoning, which may result in death. What are the causes and symptoms of maple syrup disease? How is the treatment going?

Maple Syrup Urine Disease -MSUD , also known in medical terminology as branched amino acid ketoaciduria, is genetically conditioned metabolic disorder in the course of which the body does not break down branched amino acids - leucine, isoleucine and valine (these are commonly found in food, especially those rich in protein).

As a consequence, these substances and toxic products of their decomposition (α-keto acids) accumulate in the body, which leads to its gradual poisoning, and if not treated - to death.

The prevalence of maple syrup disease is estimated at 1: 185,000, but it is much more common in some isolated populations (eg, in Pennsylvania Mennonites, in the United States, 1 in 380 babies is born with the disease). It can now be detected in tests performed as part of newborn screening.

Maple syrup disease (MSUD) - causes

The cause of maple syrup disease is a deficiency in the activity of the enzyme complex of α-keto acid dehydrogenases, responsible for the breakdown of branched amino acids in the body. It is caused by a mutation in the BCKDHA, BCKDHB, and DBT genes that contain instructions on how to make the above-mentioned. enzyme complex.

The disease is inherited in an autosomal recessive manner, ie in order for a child to become ill, he or she must receive one copy of the defective gene from each parent. If each parent carries one abnormal copy of the gene, the probability of having a child with MSUD is 25%.

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Baby's urine has a characteristic sweet smell that resembles the scent of maple syrup - hence the name of the disease.

Syrup diseasemaple tree (MSUD) - symptoms

The baby is born he althy, but usually after a few days disturbing symptoms appear, such as:

  • reluctance to eat
  • downpour
  • vomiting
  • apathy
  • sleepiness
  • tremors and convulsions
  • lax
  • breathing disorders
Important

After the onset of these symptoms, the child must be hospitalized as soon as possible. Failure to do so may result in brain damage, and further coma, as a result of the accumulation of substances produced in the body that are toxic to the child. If untreated, the disease can even lead to death.

Maple syrup disease (MSUD) - diagnosis

If a maple syrup disease is suspected, a urine and blood sample is taken (in the form of a drop of blood dried on a so-called screening paper and plasma or blood serum). Then, the laboratory analyzes the profile of organic acids in urine and blood. Final diagnosis is made when blood levels of leucine, isoleucine and valine are high.

Maple Syrup Disease (MSUD) - Treatment

In the hospital, the baby is put on a drip. Occasionally, hemodialysis or peritoneal dialysis is required to remove the toxic breakdown products of amino acids from the body.

Maple syrup disease (MSUD) - diet

For the rest of his life, the patient must follow a diet that restricts products containing the above-mentioned branched chain amino acids. They cannot be completely eliminated from the diet, because they are exogenous compounds, i.e. compounds that the body cannot produce on its own, and therefore it is necessary to provide a small amount of them with food. These compounds are part of proteins that play many important functions in the human body, including building functions - which is especially important for children.

Breastfeeding infants with MSUD is not prohibited.

Branched chain amino acid intake should be limited to only the amount required to support the normal growth of a child with MSUD. How much branched chain amino acids a child can consume with food is individual and depends on age, weight and tolerance level. With the right amount of branched acids consumed, and thus - with the correct concentrations of leucine, isoleucine and valine in the blood, the central nervous system is protected against damage.

The main sources of leucine, isoleucine and valine in the diet of MSUD patients are potatoes, vegetables, fruit and a small amount of groats and milk. These are products that are characterized by a low biological value of the protein.Safe products that do not contain protein or contain trace amounts of it are: sugar, honey, jam, jam, tea, herbal infusions, lard, margarine and vegetable oils.

In turn, the products prohibited in the diet of a patient with MSUD are meat, cold cuts, fish, eggs, milk, cheese and all products based on them. These are products that are characterized by a high biological value of the protein.

The composition of the diet depends on the current concentration of amino acids in the child's blood plasma

The patient should be under the supervision of a dietitian who, based on the current test results, compiles a menu.

Protein substitutes, free from branched chain amino acids, are a permanent element of the diet.

Maple syrup disease (MSUD) - prognosis

The prognosis of a child's psychomotor development depends on the time between the first symptoms and the diagnosis of the disease. The sooner the appropriate treatment is given, the lower the risk of damage to the nervous system.

Category:

Genetic diseases