Symptoms of Maple Syrup Urine Disease (MSUD)
Because there are a number of different forms of MSUD, the age of symptom onset, as well as certain characteristics of the symptoms can vary. There are three main types of MSUD, classic, intermediate, and intermittent. There is a thiamine responsive version also, with symptoms similar to classic MSUD. The most common from of MSUD is called "classic" MSUD. This form is harshest and most severe, and can be life-threatening. A common manifistation seen in each of the categories is maple syrup or burnt sugar smelling urine. Each type of MSUD is at risk for a syndrome called metabolic crisis. Metabolic crisis manifests as extreme sleepiness, lethargy, irritable mood, and vomiting. If not treated, seizures, coma and even death can occur. Crisis often happens after going too long wihtout food, during an illness or infection, or during stressful events such as surgery.
The best way to detect MSUD is to find it early enough before the onset of symptoms. This is a must in order to preven permanent damage. MSUD is tested in the blood sample of newborns in most states within 24 hours after birth. A blood or urine tests check for BCAAs (branched chain amino acids). To find out if your state tests for MSUD, you can go to the National Newborn Screening and Genetics Resource Center. The website address is http://genes-r-us.uthscsa.edu/ . This site gives contact infromation for each state's newborn screening program as well as direct links and information specific to the state. Early initiation of dietary intervention increases the chance for a favorable long-term outcome with reduced mortality. If MSUD is left untreated, conditions will progress to irreversible mental retardation, failure to thrive, seizures, coma, cerabral edema, and death.
The "Clasic MSUD"
In classic MSUD, there is little or no enzyme activity and symptoms usually occur within the first days of life. Although the newborn will appear normal at birth, the problems occur when feedings begins, and the intant's body is unable to break down proteins. If a newborn with MSUD has not been previously diagnosed through genetic screening, symptoms will appear within three to five days. The famous classic symptom is maple syrup odor of the urine, ear wax or other bodily fluids that smells like maple syrup or burnt sugar. Other important syptoms are poor feeding, poor appetite, weak suck, lethargy, high pitched cry, and movements that look like fencing or bicycling. The odor is evident in cerumen (ear wax) soon after birth 12-24 hours and in urine by age five to seven days.
The milder, less common forms
n milder the forms, children usually appear normal but when they eat too much proten, have an infection, surgery or other physical stress, they can develop the symptoms. Manytimes int the milder forms vomiting, staggering, confusion, and coma are the most often seen symptoms.
Intrmediate MSUD
Intermediat MSUD is found at variable ages, but usually ages five months to seven years. Patients with intermediate MSUD have more enzyme activity than classic MSUD patients, so more protein can be tolorated. The symptoms of intermediate are similar to classic MSUD, but dont get as severe as quickly. These children appear well during the neonatal period, but will still have maple syrup or burnt sugar smelling ear wax, urine, and body odor. They may present with feeding problems, poor growth and developmental delay during infancy, or present later in life with nonsyundromic mental retardation.
Intermittent MSUD
With intermittent MSUD, there is even more enzyme activity than classic or intermediate and therefore symptoms often do not occur until one to two years of age. This is because toddlers normally start eating more protein and get ill more often than other ages. When these children are well, they can tolorate proteins fairly normal or only have slight problems. It is during infections or other physicologic stress, that they develop the classic symptoms of MSUD. Symptoms are similar to clasic MSUD during times of illness.
Lifelong considerations
Children with MSUD will have a lifelong risk for episodes of ketoacidosis, and hypoglycemia. A child with MSUD should be monitored closely for growth and development. As stated earlier, for all children with MSUD the major worry is metabolic crisis. In addition to proteins in diet, illnesses or stress can cause a child to go into metabolic crisis. In order to prevent the serious outcomes associated with metabolic crisis, patients or parents should call their doctor right away when a child has any of the following: poor appetite, low energy or extreme sleepiness, vomiting, an infection or illness, fever, behavior or personality changes, and difficulty with walking or balance.
