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Maple Syrup Urine Disease Options
Posted: Wednesday, September 6, 2017 12:00:00 AM
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Maple Syrup Urine Disease

Branched chain ketoaciduria, or maple syrup urine disease (MSUD), is a metabolic disorder in which an enzyme deficiency allows branched-chain amino acids to build up in the blood and urine. Often diagnosed in infancy, the condition gets its name from the distinctive sweet odor—similar to that of maple syrup or burnt caramel—of the sufferer's urine. If left untreated, MSUD can cause severe brain damage or death. Why is the disease more prevalent in children of Amish and Mennonite descent? More...
Posted: Wednesday, September 6, 2017 4:12:14 AM

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I was relieved to read that the condition is NOT caused by maple syrup.Anxious
Posted: Wednesday, September 6, 2017 4:35:30 AM

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I was more concerned that maple syrup urinated!

Do not piss against a maple tree. It might piss back at you.

raghd muhi al-deen
Posted: Wednesday, September 6, 2017 9:06:50 AM

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maple syrup urine disease
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Related to maple syrup urine disease: maple syrup diet
Maple syrup urine disease
Maple syrup urine disease
Classification and external resources

Isoleucine (pictured above), leucine, and valine are the branched-chain amino acids that build up in MSUD.
ICD-10 E71.0
ICD-9 270.3
OMIM 248600
DiseasesDB 7820
MedlinePlus 000373
eMedicine ped/1368
MeSH D008375

Maple syrup urine disease (MSUD), also called branched-chain ketoaciduria, is an autosomal recessive[1] metabolic disorder affecting branched-chain amino acids. It is one type of organic acidemia.[2] The condition gets its name from the distinctive sweet odor of affected infants' urine.[3]

MSUD is a metabolic disorder caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex (BCKDC), leading to a buildup of the branched-chain amino acids (leucine, isoleucine, and valine) and their toxic by-products (ketoacids) in the blood and urine. The enzyme complex consists of four subunits designated E1α, E1β, E2, and E3. The E3 subunit is also a component of pyruvate dehydrogenase complex and oxoglutarate dehydrogenase complex.[4] MSUD can result from mutations in any of the genes that code for the enzyme subunits.
Diagnosis and symptoms

The disease is named for the presence of sweet-smelling urine, with an odor similar to that of maple syrup. The smell is also present and sometimes stronger in the ear wax of an affected individual. Prior to the easy availability of plasma amino acid measurement, diagnosis was commonly made based on suggestive symptoms and odor. Affected individuals are now often identified with characteristic elevations on plasma amino acids who do not have the characteristic odor.[5] The compound responsible for the odor is sotolon (sometimes spelled sotolone).[6] Infants with this disease seem healthy at birth but if left untreated suffer severe brain damage and eventually die.

From early infancy, symptoms of the condition include poor feeding, vomiting, dehydration, lethargy, hypotonia, seizures, hypoglycaemia, ketoacidosis, opisthotonus, pancreatitis, coma and neurological decline.

Maple syrup urine disease can be classified by its pattern of signs and symptoms, or by its genetic cause. The most common and severe form of the disease is the classic type, which appears soon after birth. Variant forms of the disorder may appear later in infancy or childhood and are typically less severe, but still involve mental and physical problems if left untreated.

There are several variations of the disease:

Classic Severe MSUD
Intermediate MSUD
Intermittent MSUD
Thiamine-responsive MSUD
E3-Deficient MSUD with Lactic Acidosis


Keeping MSUD under control requires careful monitoring of blood chemistry and involves both a special diet and frequent testing.

A diet with minimal levels of the amino acids leucine, isoleucine, and valine must be maintained in order to prevent neurological damage. As these three amino acids are required for proper metabolic function in all humans, specialized protein preparations containing substitutes and adjusted levels of the amino acids have been synthesized and tested, allowing MSUD patients to meet normal nutritional requirements without causing harm.[7] Some patients with MSUD may also improve with administration of high doses of thiamine, a cofactor of the enzyme that causes the condition.

Usually, patients are also monitored by a dietitian. Their diet must be adhered to strictly and permanently. However, with proper management, those afflicted are able to live healthy, normal lives and not suffer the severe neurological damage associated with the disease.
Genetic prevalence
Maple syrup urine disease has an autosomal recessive pattern of inheritance.

Maple syrup urine disease affects approximately 1 out of 180,000 infants.[8] Due in part to the founder effect,[9] however, MSUD has a much higher prevalence in children of Amish, Mennonite, and Jewish descent.[10][8][11]

Mutations in the following genes cause maple syrup urine disease:

BCKDHA (Online 'Mendelian Inheritance in Man' (OMIM) 608348)
BCKDHB (Online 'Mendelian Inheritance in Man' (OMIM) 248611)
DBT (Online 'Mendelian Inheritance in Man' (OMIM) 248610)
DLD (Online 'Mendelian Inheritance in Man' (OMIM) 238331)

These four genes produce proteins that work together as the branched-chain alpha-keto acid dehydrogenase complex. The complex is essential for breaking down the amino acids leucine, isoleucine, and valine, which are present in many kinds of food (in particular, protein-rich foods such as milk, meat, and eggs). Mutations in any of these genes reduce or eliminate the function of the enzyme complex, preventing the normal breakdown of isoleucine, leucine, and valine. As a result, these amino acids and their by-products build up in the body. Because high levels of these substances are toxic to the brain and other organs, this accumulation leads to the serious medical problems associated with maple syrup urine disease.

This condition has an autosomal recessive inheritance pattern, which means the defective gene is located on an autosome, and two copies of the gene - one from each parent - must be inherited to be affected by the disorder. The parents of a child with an autosomal recessive disorder are carriers of one copy of the defective gene, but are usually not affected by the disorder.

with my pleasure
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