Biotin, also called vitamin B7, is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name biotin derives from the Greek word “bios” (to live) and the suffix “-in” (a general chemical suffix used in organic chemistry).
Abetalipoproteinemia is a disorder that interferes with the normal absorption of fat and fat-soluble vitamins from food. It is caused by a mutation in microsomal triglyceride transfer protein resulting in deficiencies in the apolipoproteins B-48 and B-100, which are used in the synthesis and exportation of chylomicrons and VLDL respectively. It is not to be confused with familial dysbetalipoproteinemia.
Porphyria cutanea tarda is the most common subtype of porphyria. The disease is named because it is a porphyria that often presents with skin manifestations later in life. The disorder results from low levels of the enzyme responsible for the fifth step in heme production. Heme is a vital molecule for all of the body's organs. It is a component of hemoglobin, the molecule that carries oxygen in the blood.
Isovaleric acidemia is a rare autosomal recessive metabolic disorder which disrupts or prevents normal metabolism of the branched-chain amino acid leucine. It is a classical type of organic acidemia.
Citrullinemia is an autosomal recessive urea cycle disorder that causes ammonia and other toxic substances to accumulate in the blood.
3-Hydroxy-3-methylglutaryl-CoA lyase deficiency is an uncommon inherited disorder in which the body cannot properly process the amino acid leucine. Additionally, the disorder prevents the body from making ketones, which are used for energy during fasting.
Carnitine palmitoyltransferase I deficiency is a rare metabolic disorder that prevents the body from converting certain fats called long-chain fatty acids 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 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.
Biotinidase deficiency is an autosomal recessive metabolic disorder in which biotin is not released from proteins in the diet during digestion or from normal protein turnover in the cell. This situation results in biotin deficiency.
HLCS, also known as protein–biotin ligase, is a family of enzymes. This enzyme is important for the effective use of biotin, a B vitamin found in foods such as liver, egg yolks, and milk. In many of the body's tissues, holocarboxylase synthetase activates other specific enzymes by attaching biotin to them. These carboxylases are involved in many critical cellular functions, including the production and breakdown of proteins, fats, and carbohydrates.
3-Methylcrotonyl-CoA carboxylase deficiency also known as 3-Methylcrotonylglycinuria or BMCC deficiency is an inherited disorder in which the body is unable to process certain proteins properly. People with this disorder have inadequate levels of an enzyme that helps break down proteins containing the amino acid leucine. This condition affects an estimated 1 in 50,000 individuals worldwide.
Carbamoyl phosphate synthetase I deficiency is an autosomal recessive metabolic disorder that causes ammonia to accumulate in the blood due to a lack of the enzyme carbamoyl phosphate synthetase I. Ammonia, which is formed when proteins are broken down in the body, is toxic if the levels become too high. The nervous system is especially sensitive to the effects of excess ammonia.
Glutathione synthetase deficiency (GSD) is a rare autosomal recessive metabolic disorder that prevents the production of glutathione. Glutathione helps prevent damage to cells by neutralizing harmful molecules generated during energy production. Glutathione also plays a role in processing medications and cancer-causing compounds (carcinogens), and building DNA, proteins, and other important cellular components.
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.
Biotinidase is an enzyme that in humans is encoded by the BTD gene.
Biotin deficiency is a nutritional disorder which can become serious, even fatal, if allowed to progress untreated. It can occur in people of any age, ancestry, or gender. Biotin is part of the B vitamin family. Biotin deficiency rarely occurs among healthy people because the daily requirement of biotin is low, many foods provide adequate amounts of it, intestinal bacteria synthesize small amounts of it, and the body effectively scavenges and recycles it in the kidneys during production of urine. However, deficiencies can be caused by consuming raw egg whites over a period of weeks to months. Egg whites contain high levels of avidin, a protein that binds biotin strongly. When cooked, avidin is partially denatured and binding to biotin is reduced. However one study showed that 30-40% of the avidin activity was still present in the white after frying or boiling. Genetic disorders such as biotinidase deficiency, multiple carboxylase deficiency, and holocarboxylase synthetase deficiency can also lead to inborn or late-onset forms of biotin deficiency. In all cases – dietary, genetic, or otherwise – supplementation with biotin is the primary method of treatment.
Galactosialidosis, also known as Neuraminidase deficiency with beta-galactosidase deficiency, is a genetic lysosomal storage disease. It is caused by a mutation in the CTSA gene which leads to a deficiency of enzymes β-galactosidase and neuraminidase. This deficiency inhibits the lysosomes of cells from functioning properly, resulting in the accumulation of toxic matter within the cell. Hallmark symptoms include abnormal spinal structure, vision problems, coarse facial features, hearing impairment, and intellectual disability. Because galactosialidosis involves the lysosomes of all cells, it can affect various areas of the body, including the brain, eyes, bones, and muscles. Depending on the patient's age at the onset of symptoms, the disease consists of three subtypes: early infantile, late infantile, and juvenile/adult. This condition is considered rare, with most cases having been in the juvenile/adult group of patients.
Argininemia, is an autosomal recessive urea cycle disorder where a deficiency of the enzyme arginase causes a buildup of arginine and ammonia in the blood. Ammonia, which is formed when proteins are broken down in the body, is toxic if levels become too high; the nervous system is especially sensitive to the effects of excess ammonia.
