Information for Patients
Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system break the food parts down into sugars and acids, your body's fuel. Your body can use this fuel right away, or it can store the energy in your body tissues, such as your liver, muscles, and body fat.
A metabolic disorder occurs when abnormal chemical reactions in your body disrupt this process. When this happens, you might have too much of some substances or too little of other ones that you need to stay healthy. There are different groups of disorders. Some affect the breakdown of amino acids, carbohydrates, or lipids. Another group, mitochondrial diseases, affects the parts of the cells that produce the energy.
You can develop a metabolic disorder when some organs, such as your liver or pancreas, become diseased or do not function normally. Diabetes is an example.
- Acidosis (Medical Encyclopedia)
- Alkalosis (Medical Encyclopedia)
- Lactic acid test (Medical Encyclopedia)
- Metabolic acidosis (Medical Encyclopedia)
- Metabolic neuropathies (Medical Encyclopedia)
- Pseudohypoparathyroidism (Medical Encyclopedia)
Dilated cardiomyopathy with ataxia syndrome Dilated cardiomyopathy with ataxia (DCMA) syndrome is an inherited condition characterized by heart problems, movement difficulties, and other features affecting multiple body systems.Beginning in infancy to early childhood, most people with DCMA syndrome develop dilated cardiomyopathy, which is a condition that weakens and enlarges the heart, preventing it from pumping blood efficiently. Some affected individuals also have long QT syndrome, which is a heart condition that causes the cardiac muscle to take longer than usual to recharge between beats. The irregular heartbeats (arrhythmia) can lead to fainting (syncope) or cardiac arrest and sudden death. Rarely, heart problems improve over time; however, in most cases of DCMA syndrome, affected individuals do not survive past childhood due to heart failure. A small percentage of people with DCMA syndrome have no heart problems at all.By age 2, children with DCMA syndrome have problems with coordination and balance (ataxia). These movement problems can result in delay of motor skills such as standing and walking, but most older children with DCMA syndrome can walk without support.In addition to heart problems and movement difficulties, most individuals with DCMA syndrome grow slowly before and after birth, which leads to short stature. Additionally, many affected individuals have mild intellectual disability. Many males with DCMA syndrome have genital abnormalities such as undescended testes (cryptorchidism) or the urethra opening on the underside of the penis (hypospadias). Other common features of DCMA syndrome include unusually small red blood cells (microcytic anemia), which can cause pale skin; an abnormal buildup of fats in the liver (hepatic steatosis), which can damage the liver; and the degeneration of nerve cells that carry visual information from the eyes to the brain (optic nerve atrophy), which can lead to vision loss.DCMA syndrome is associated with increased levels of a substance called 3-methylglutaconic acid in the urine. The amount of acid does not appear to influence the signs and symptoms of the condition. DCMA syndrome is one of a group of metabolic disorders that can be diagnosed by the presence of increased levels of 3-methylglutaconic acid in urine (3-methylglutaconic aciduria). People with DCMA syndrome also have high urine levels of another acid called 3-methylglutaric acid.
Costeff syndrome Costeff syndrome is an inherited condition characterized by vision loss, delayed development, and movement problems. Vision loss is primarily caused by degeneration (atrophy) of the optic nerves, which carry information from the eyes to the brain. This optic nerve atrophy often begins in infancy or early childhood and results in vision impairment that worsens over time. Some affected individuals have rapid and involuntary eye movements (nystagmus) or eyes that do not look in the same direction (strabismus).Development of motor skills, such as walking, is often delayed in people with Costeff syndrome. Affected individuals may also have speech difficulties (dysarthria). While some people with Costeff syndrome have mild to moderate intellectual disability, many have normal intelligence.Movement problems in people with Costeff syndrome develop in late childhood and include muscle stiffness (spasticity), impaired muscle coordination (ataxia), and involuntary jerking movements (choreiform movements). As a result of these movement difficulties, individuals with Costeff syndrome may require wheelchair assistance.Costeff syndrome is associated with increased levels of a substance called 3-methylglutaconic acid in the urine (3-methylglutaconic aciduria). The amount of this substance does not appear to influence the signs and symptoms of the condition. Costeff syndrome is one of a group of metabolic disorders that can be diagnosed by the presence of 3-methylglutaconic aciduria. People with Costeff syndrome also have high levels of another acid called 3-methylglutaric acid in their urine.
MEGDEL syndrome MEGDEL syndrome is an inherited disorder that affects multiple body systems. It is named for several of its features: 3-methylglutaconic aciduria (MEG), deafness (D), encephalopathy (E), and Leigh-like disease (L).MEGDEL syndrome is characterized by abnormally high levels of an acid, called 3-methylglutaconic acid, in the urine (3-methylglutaconic aciduria). MEGDEL syndrome is one of a group of metabolic disorders that can be diagnosed by presence of this feature. People with MEGDEL syndrome also have high urine levels of another acid called 3-methylglutaric acid.In infancy, individuals with MEGDEL syndrome develop hearing loss caused by changes in the inner ear (sensorineural deafness); the hearing problems gradually worsen over time.Another feature of MEGDEL syndrome is brain dysfunction (encephalopathy). In infancy, encephalopathy leads to difficulty feeding, an inability to grow and gain weight at the expected rate (failure to thrive), and weak muscle tone (hypotonia). Infants with MEGDEL syndrome later develop involuntary muscle tensing (dystonia) and muscle stiffness (spasticity), which worsen over time. Because of these brain and muscle problems, affected babies have delayed development of mental and movement abilities (psychomotor delay), or they may lose skills they already developed. Individuals with MEGDEL syndrome have intellectual disability and never learn to speak.People with MEGDEL syndrome have changes in the brain that resemble those in another condition called Leigh syndrome. These changes, which can be seen with medical imaging, are referred to as Leigh-like disease.Other features that occur commonly in MEGDEL syndrome include low blood sugar (hypoglycemia) in affected newborns; liver problems (hepatopathy) in infancy, which can be serious but improve by early childhood; and episodes of abnormally high amounts of lactic acid in the blood (lactic acidosis).The life expectancy of individuals with MEGDEL syndrome is unknown. Because of the severe health problems caused by the disorder, some affected individuals do not survive past infancy.
3-methylglutaconyl-CoA hydratase deficiency 3-methylglutaconyl-CoA hydratase deficiency is an inherited condition that causes neurological problems. Beginning in infancy to early childhood, children with this condition often have delayed development of mental and motor skills (psychomotor delay), speech delay, involuntary muscle cramping (dystonia), and spasms and weakness of the arms and legs (spastic quadriparesis). Affected individuals can also have optic atrophy, which is the degeneration (atrophy) of nerve cells that carry visual information from the eyes to the brain.In some cases, signs and symptoms of 3-methylglutaconyl-CoA hydratase deficiency begin in adulthood, often in a person's twenties or thirties. These individuals have damage to a type of brain tissue called white matter (leukoencephalopathy), which likely contributes to progressive problems with speech (dysarthria), difficulty coordinating movements (ataxia), stiffness (spasticity), optic atrophy, and a decline in intellectual function (dementia).Affected individuals who show symptoms of 3-methylglutaconyl-CoA hydratase deficiency in childhood often go on to develop leukoencephalopathy and other neurological problems in adulthood.All people with 3-methylglutaconyl-CoA hydratase deficiency accumulate large amounts of a substance called 3-methylglutaconic acid in their body fluids. As a result, they have elevated levels of acid in their blood (metabolic acidosis) and excrete large amounts of acid in their urine (aciduria). 3-methylglutaconyl-CoA hydratase deficiency is one of a group of metabolic disorders that can be diagnosed by the presence of increased levels 3-methylglutaconic acid in urine (3-methylglutaconic aciduria). People with 3-methylglutaconyl-CoA hydratase deficiency also have high urine levels of another acid called 3-methylglutaric acid.