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Very long-chain acyl-coenzyme A dehydrogenase deficiency | |
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Other names | VLCADD |
Very long-chain acyl-coenzyme: A dehydrogenase deficiency has an autosomal recessive pattern of inheritance. |
Very long-chain acyl-coenzyme A dehydrogenase deficiency is a fatty-acid metabolism disorder which prevents the body from converting certain fats to energy, particularly during periods without food. [1] [2] [3]
Those affected by this disorder have inadequate levels of an enzyme that breaks down a group of fats called very long-chain fatty acids.[ citation needed ] [4]
Signs and symptoms can include: [5] [6]
VLCAD (very long-chain-acyl-dehydrogenase) deficiency is exclusively linked to genetic mutations in DNA. A change of the gene that codes for very long-chain-acyl-CoA-dehydrogenase (VLCAD) results in a deficiency or malfunction of the produced VLCAD enzyme. [7] This mutation occurs on chromosome 17 and can be altered via a variety of pathways. [4] These can range from frameshift mutations, deletion mutations, insertion mutations, and missense mutations. All of which cause the enzyme to function differently in the mitochondria, or in some cases not at all. [4] Due to this mutation, effective levels of very long-chain-acyl-CoA-dehydrogenase are low or absent in the body, giving rise to the array of symptoms listed above. [4] [7]
Mutations in the ACADVL gene lead to inadequate levels of an enzyme called very long-chain acyl-coenzyme A (CoA) dehydrogenase. Without this enzyme, long-chain fatty acids from food and fats stored in the body cannot be degraded and processed. As a result, these fatty acids are not converted into energy, which can lead to characteristic signs and symptoms of this disorder, such as lethargy and hypoglycemia. Levels of very long-chain fatty acids or partially degraded fatty acids may build up in tissues and can damage the heart, liver, and muscles, causing more serious complications.[ citation needed ]
VLCAD deficiency is characterized as an inherited genetic disorder. The mutations that occur within the gene itself are recessive, meaning that an individual has to acquire both recessive mutated genes in order for the disease to manifest. [4] There are various forms of the disease that can be manifested in infancy, adolescence, and adulthood. [8] However, it is still unknown at to what causes the disease to manifest itself in the different life stages.[ citation needed ]
Typically, initial signs and symptoms of this disorder occur during infancy and include low blood sugar (hypoglycemia), lack of energy (lethargy), and muscle weakness. There is also a high risk of complications such as liver abnormalities and life-threatening heart problems. Symptoms that begin later in childhood, adolescence, or adulthood tend to be milder and usually do not involve heart problems. Episodes of very long-chain acyl-coenzyme A dehydrogenase deficiency can be triggered by periods of fasting, illness, and exercise.[ citation needed ]
It is common for babies and children with the early and childhood types of VLCAD to have episodes of illness known as metabolic crises. Some of the first symptoms of a metabolic crisis are: extreme sleepiness, behavior changes, irritable mood, poor appetite. Some of these other symptoms of VLCAD in infants may also follow: fever, nausea, diarrhea, vomiting, hypoglycemia. Evaluation of symptom combinations can aid in a positive diagnosis of VLCAD. [9] Since symptoms vary depending on age and onset of the patient, consultation with a metabolic specialist should be considered. Diagnosis is further confirmed through genetic analysis of the VLCAD gene. [9]
Treatment and management of VLCAD deficiency involve dietary restrictions as well as implementation of proper hydration to avoid further complications. Hospitalization due to VLCAD deficiency can be treated with intravenous (IV) glucose for hydration and alkalization of urine and prevention of renal malfunction or failure. [10] Avoidance of fasting periods, high-fat diets, and dehydration is recommended for those who are affected. A diet consisting of low-fat intake and supplemental calories is common for management of VLCAD deficiency. If a metabolic crisis is not treated, a child with VLCAD can develop: breathing problems, seizures, coma, sometimes leading to death.[ citation needed ]
Medical screening can confirm occurrences of VLCAD most often in neonatal and infancy stages. Approximately half of all patients show signs of VLCAD deficiency during the neonatal period, one-fourth present later in the first year of infancy, and the final quarter is split between manifestations in childhood and adulthood.[ citation needed ] Comorbidity of cardiomyopathy, arrhythmias [3] and rhabdomyolysis are extremely common in patients under 1 year old which can lead to complications later in life[ citation needed ]. Loss of awareness or seizure can occur from hypoketotic hypoglycemia, [3] which is often fatal if not caught in screening. However, prompt treatment shows high promise for improvement. People who develop late-onset myopathic may only experience muscle-related, vague, sporadic symptoms, and may never be diagnosed. [3] There is an extremely high genotype-phenotype correlation in a presentation. Mitigation of VLCAD symptoms can be achieved through dietary management[ citation needed ].
Medium-chain acyl-CoA dehydrogenase deficiency is a disorder of fatty acid oxidation that impairs the body's ability to break down medium-chain fatty acids into acetyl-CoA. The disorder is characterized by hypoglycemia and sudden death without timely intervention, most often brought on by periods of fasting or vomiting.
Long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency is a rare autosomal recessive fatty acid oxidation disorder that prevents the body from converting certain fats into energy. This can become life-threatening, particularly during periods of fasting.
Numerous genetic disorders are caused by errors in fatty acid metabolism. These disorders may be described as fatty oxidation disorders or as a lipid storage disorders, and are any one of several inborn errors of metabolism that result from enzyme defects affecting the ability of the body to oxidize fatty acids in order to produce energy within muscles, liver, and other cell types.
Carnitine palmitoyltransferase I deficiency is a rare metabolic disorder that prevents the body from converting certain fats called long-chain fatty acids(LCFA) into energy, particularly during periods without food. It is caused by a mutation in CPT1A on chromosome 11.
Carnitine-acylcarnitine translocase deficiency is a rare, autosomal recessive metabolic disorder that prevents the body from converting long-chain fatty acids into energy, particularly during periods without food. Carnitine, a natural substance acquired mostly through the diet, is used by cells to process fats and produce energy. People with this disorder have a faulty enzyme that prevents long-chain fatty acids from being transported into the innermost part of the mitochondria for processing.
Mitochondrial trifunctional protein deficiency is an autosomal recessive fatty acid oxidation disorder that prevents the body from converting certain fats to energy, particularly during periods without food. People with this disorder have inadequate levels of an enzyme that breaks down a certain group of fats called long-chain fatty acids.
Very long-chain specific acyl-CoA dehydrogenase, mitochondrial (VLCAD) is an enzyme that in humans is encoded by the ACADVL gene.
ACADM is a gene that provides instructions for making an enzyme called acyl-coenzyme A dehydrogenase that is important for breaking down (degrading) a certain group of fats called medium-chain fatty acids.
Glutaric acidemia type 2 is an autosomal recessive metabolic disorder that is characterised by defects in the ability of the body to use proteins and fats for energy. Incompletely processed proteins and fats can build up, leading to a dangerous chemical imbalance called acidosis.
Malonyl-CoA decarboxylase deficiency (MCD) is an autosomal-recessive metabolic disorder caused by a genetic mutation that disrupts the activity of Malonyl-CoA decarboxylase. This enzyme breaks down Malonyl-CoA into acetyl-CoA and carbon dioxide.
Short-chain acyl-coenzyme A dehydrogenase deficiency (SCADD) is an autosomal recessive fatty acid oxidation disorder which affects enzymes required to break down a certain group of fats called short chain fatty acids.
Acyl-CoA dehydrogenases (ACADs) are a class of enzymes that function to catalyze the initial step in each cycle of fatty acid β-oxidation in the mitochondria of cells. Their action results in the introduction of a trans double-bond between C2 (α) and C3 (β) of the acyl-CoA thioester substrate. Flavin adenine dinucleotide (FAD) is a required co-factor in addition to the presence of an active site glutamate in order for the enzyme to function.
Acyl-CoA dehydrogenase, C-2 to C-3 short chain is an enzyme that in humans is encoded by the ACADS gene. This gene encodes a tetrameric mitochondrial flavoprotein, which is a member of the acyl-CoA dehydrogenase family. This enzyme catalyzes the initial step of the mitochondrial fatty acid beta-oxidation pathway. The ACADS gene associated with short-chain acyl-coenzyme A dehydrogenase deficiency.
Isobutyryl-coenzyme A dehydrogenase deficiency is a rare metabolic disorder in which the body is unable to process certain amino acids properly.
Acyl-CoA is a group of coenzymes that metabolize fatty acids. Acyl-CoA's are susceptible to beta oxidation, forming, ultimately, acetyl-CoA. The acetyl-CoA enters the citric acid cycle, eventually forming several equivalents of ATP. In this way, fats are converted to ATP, the universal biochemical energy carrier.
3-hydroxyacyl-coenzyme A dehydrogenase deficiency is a rare condition that prevents the body from converting certain fats to energy, particularly during fasting. Normally, through a process called fatty acid oxidation, several enzymes work in a step-wise fashion to metabolize fats and convert them to energy. People with 3-hydroxyacyl-coenzyme A dehydrogenase deficiency have inadequate levels of an enzyme required for a step that metabolizes groups of fats called medium chain fatty acids and short chain fatty acids; for this reason this disorder is sometimes called medium- and short-chain 3-hydroxyacyl-coenzyme A dehydrogenase (M/SCHAD) deficiency.
ACADSB is a human gene that encodes short/branched chain specific acyl-CoA dehydrogenase (SBCAD), an enzyme in the acyl CoA dehydrogenase family.
Electron-transferring-flavoprotein dehydrogenase is an enzyme that transfers electrons from electron-transferring flavoprotein in the mitochondrial matrix, to the ubiquinone pool in the inner mitochondrial membrane. It is part of the electron transport chain. The enzyme is found in both prokaryotes and eukaryotes and contains a flavin and FE-S cluster. In humans, it is encoded by the ETFDH gene. Deficiency in ETF dehydrogenase causes the human genetic disease multiple acyl-CoA dehydrogenase deficiency.
A broad classification for genetic disorders that result from an inability of the body to produce or utilize an enzyme or transport protein that is required to oxidize fatty acids. They are an inborn error of lipid metabolism, and when it affects the muscles also a metabolic myopathy.
Hydroxyacyl-Coenzyme A dehydrogenase (HADH) is an enzyme which in humans is encoded by the HADH gene.