Fucosidosis | |
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Other names | Alpha-L-fucosidase deficiency [1] |
Fucose | |
Specialty | Endocrinology |
Fucosidosis is a rare lysosomal storage disorder [2] in which the FUCA1 gene experiences mutations that severely reduce or stop the activity of the alpha-L-fucosidase enzyme. [3] The result is a buildup of complex sugars in parts of the body, which leads to death. Fucosidosis is one of nine identified glycoprotein storage diseases. The gene encoding the alpha-fucosidase, FUCA 1, was found to be located to the short arm of chromosome 1p36 - p34, [4] by Carrit and co-workers, in 1982.
Fucosidosis is an autosomal recessive disorder that affects many areas of the body. Mutations in the FUCA1 gene cause fucosidosis. The FUCA1 gene provides instructions for making an enzyme called alpha-L-fucosidase. The enzyme plays a role in the breakdown of complex sugars in the body. [3] The deficiency of the enzyme alpha-L-fucosidase, which is used to metabolize complex compounds in the body (fucose-containing glycolipids and fucose-containing glycoproteins), leads to lysosomal accumulation of a variety of glycoproteins, glycolipids, and oligosaccharides that contain fucose moieties. [2] [4] The result is incomplete breakdown of glycolipids and glycoproteins. These partially broken down compounds accumulate in various parts of the body and begin to cause malfunction in cells, [3] and can eventually cause cell death. Brain cells are especially sensitive to this buildup. Other results are progressive neurological deterioration, skin abnormalities, growth retardation, skeletal disease, and coarsening of facial features. [2] Fucosidosis is the consequence of faulty degradation of both sphingolipids and polysaccharides. Major accumulation of the H-antigen (a member of the ABO blood group antigens), a glycolipid, is seen primarily in the liver of fucosidosis patients; some researchers have speculated that blood type may play a role in the course of the disease. [4] [5]
A special urine test is available to check for any partially broken-down sugars. If they are present, a skin or blood sample will be taken to test for below-normal amounts of alpha-fucosidase. [2]
Fucosidosis is an autosomal recessive disorder, which means that both parents have to have the mutation and pass it on to the child. When both parents have the mutation, there is a 25% chance of each child having fucosidosis. [2]
The condition was traditionally separated by type, with type 1 beginning sooner, progressing more quickly, and being more severe, and type 2 being milder and progressing more slowly; a third, even milder form has also been recognized. [6] Fucosidosis is now considered to be a single disorder and "represents a disease spectrum with a wide variety of expression." [7] More severe forms (type 1) appear in the first 3 to 18 months of life, while milder forms typically appear between 12 and 24 months. [8]
Symptoms are highly variable, with mild cases being able to live to within the third or fourth decade. [6]
Symptoms include: [8]
Severe cases can develop life-threatening complications early in childhood. In the more severe forms (type 1), "patients have no vascular lesions, but have rapid psychomotor regression, severe and rapidly progressing neurologic signs, elevated sodium and chloride excretion in the sweat, and fatal outcome before the sixth year." [9]
More severe forms are linked with mental retardation. [6]
There is no treatment or way to reverse the disease; treatment instead focuses on the individual's symptoms, such as seizure medication. [10]
Research into bone marrow transplants, in an attempt to improve enzyme activity, is ongoing as of 2023 [update] . [7]
Fucosidosis is an extremely rare disorder first described in 1962 in two Italian siblings who showed progressive intellectual disability and neurological deterioration. The disease itself is extremely rare (less than 100 documented cases [3] ) only affecting 1:2,000,000, [2] with most cases occurring in Italy, Cuba, and the southwest U.S. [2] [11]
Canine fucosidosis is found in the English Springer Spaniel. [12]
Typically affecting dogs between 18 months and four years,[ citation needed ] symptoms include: [13] [14]
From the onset, disease progress is quick and fatal.
As in the human version, canine fucosidosis is a recessive disorder and two copies of the gene must be present, one from each parent, in order to show symptoms of the disease. [13]
Gaucher's disease or Gaucher disease (GD) is a genetic disorder in which glucocerebroside accumulates in cells and certain organs. The disorder is characterized by bruising, fatigue, anemia, low blood platelet count and enlargement of the liver and spleen, and is caused by a hereditary deficiency of the enzyme glucocerebrosidase, which acts on glucocerebroside. When the enzyme is defective, glucocerebroside accumulates, particularly in white blood cells and especially in macrophages. Glucocerebroside can collect in the spleen, liver, kidneys, lungs, brain, and bone marrow.
Lysosomal storage diseases are a group of over 70 rare inherited metabolic disorders that result from defects in lysosomal function. Lysosomes are sacs of enzymes within cells that digest large molecules and pass the fragments on to other parts of the cell for recycling. This process requires several critical enzymes. If one of these enzymes is defective due to a mutation, the large molecules accumulate within the cell, eventually killing it.
Alpha-mannosidosis is a lysosomal storage disorder, first described by Swedish physician Okerman in 1967. In humans it is known to be caused by an autosomal recessive genetic mutation in the gene MAN2B1, located on chromosome 19, affecting the production of the enzyme alpha-D-mannosidase, resulting in its deficiency. Consequently, if both parents are carriers, there will be a 25% chance with each pregnancy that the defective gene from both parents will be inherited, and the child will develop the disease. There is a two in three chance that unaffected siblings will be carriers. In livestock alpha-mannosidosis is caused by chronic poisoning with swainsonine from locoweed.
Phosphofructokinase deficiency is a rare muscular metabolic disorder, with an autosomal recessive inheritance pattern. It is characterized as a deficiency in the Phosphofructokinase (PFK) enzyme throughout the body, including the skeletal muscles and red blood cells. Phosphofrucotkinase is an enzyme involved in the glycolytic process. The lack of PFK blocks the completion of the glycolytic pathway. Therefore, all products past the block would be deficient, including Adenosine triphosphate (ATP).
Sandhoff disease is a lysosomal genetic, lipid storage disorder caused by the inherited deficiency to create functional beta-hexosaminidases A and B. These catabolic enzymes are needed to degrade the neuronal membrane components, ganglioside GM2, its derivative GA2, the glycolipid globoside in visceral tissues, and some oligosaccharides. Accumulation of these metabolites leads to a progressive destruction of the central nervous system and eventually to death. The rare autosomal recessive neurodegenerative disorder is clinically almost indistinguishable from Tay–Sachs disease, another genetic disorder that disrupts beta-hexosaminidases A and S. There are three subsets of Sandhoff disease based on when first symptoms appear: classic infantile, juvenile and adult late onset.
Mucolipidosis type I is an inherited lysosomal storage disease that results from a deficiency of the enzyme alpha-N -acetyl neuraminidase (sialidase). The lack of this enzyme results in an abnormal accumulation of complex carbohydrates known as mucopolysaccharides, and of fatty substances known as mucolipids. Both of these substances accumulate in bodily tissues.
A lipid storage disorder is any one of a group of inherited metabolic disorders in which harmful amounts of fats or lipids accumulate in some body cells and tissues. People with these disorders either do not produce enough of one of the enzymes needed to metabolize and break down lipids or, they produce enzymes that do not work properly. Over time, the buildup of fats may cause permanent cellular and tissue damage, particularly in the brain, peripheral nervous system, liver, spleen, and bone marrow.
Mannosidosis is a deficiency in mannosidase, an enzyme. There are two types: alpha-mannosidosis and beta-mannosidosis. Both disorders are related to the lysosome and have similar presentation; the former is caused by defective lysosomal α-mannosidase and the latter by defective lysosomal β-mannosidase. In both cases, the defect causes accumulation of oligosaccharides rich in mannose in the neural tissue and organ tissue. Both alpha- and beta-mannosidosis are known to result from autosomal recessive genetic mutations.
Glycoproteinosis are lysosomal storage diseases affecting glycoproteins, resulting from defects in lysosomal function. The term is sometimes reserved for conditions involving degradation of glycoproteins.
Inclusion-cell (I-cell) disease, also referred to as mucolipidosis II, is part of the lysosomal storage disease family and results from a defective phosphotransferase. This enzyme transfers phosphate to mannose residues on specific proteins. Mannose-6-phosphate serves as a marker for proteins to be targeted to lysosomes within the cell. Without this marker, proteins are instead secreted outside the cell, which is the default pathway for proteins moving through the Golgi apparatus. Lysosomes cannot function without these proteins, which function as catabolic enzymes for the normal breakdown of substances in various tissues throughout the body. As a result, a buildup of these substances occurs within lysosomes because they cannot be degraded, resulting in the characteristic I-cells, or "inclusion cells" seen microscopically. In addition, the defective lysosomal enzymes normally found only within lysosomes are instead found in high concentrations in the blood, but they remain inactive at blood pH because they require the low lysosomal pH 5 to function.
Tissue alpha-L-fucosidase is an enzyme that in humans is encoded by the FUCA1 gene.
Progressive Myoclonic Epilepsies (PME) are a rare group of inherited neurodegenerative diseases characterized by myoclonus, resistance to treatment, and neurological deterioration. The cause of PME depends largely on the type of PME. Most PMEs are caused by autosomal dominant or recessive and mitochondrial mutations. The location of the mutation also affects the inheritance and treatment of PME. Diagnosing PME is difficult due to their genetic heterogeneity and the lack of a genetic mutation identified in some patients. The prognosis depends largely on the worsening symptoms and failure to respond to treatment. There is no current cure for PME and treatment focuses on managing myoclonus and seizures through antiepileptic medication (AED).
Beta-mannosidosis, also called lysosomal beta-mannosidase deficiency, is a disorder of oligosaccharide metabolism caused by decreased activity of the enzyme beta-mannosidase. This enzyme is coded for by the gene MANBA, located at 4q22-25. Beta-mannosidosis is inherited in an autosomal recessive manner. Affected individuals appear normal at birth, and can have a variable clinical presentation. Infantile onset forms show severe neurodegeneration, while some children have intellectual disability. Hearing loss and angiokeratomas are common features of the disease.
Jansky–Bielschowsky disease is an extremely rare autosomal recessive genetic disorder that is part of the neuronal ceroid lipofuscinosis (NCL) family of neurodegenerative disorders. It is caused by the accumulation of lipopigments in the body due to a deficiency in tripeptidyl peptidase I as a result of a mutation in the TPP1 gene. Symptoms appear between ages 2 and 4 and consist of typical neurodegenerative complications: loss of muscle function (ataxia), drug resistant seizures (epilepsy), apraxia, development of muscle twitches (myoclonus), and vision impairment. This late-infantile form of the disease progresses rapidly once symptoms are onset and ends in death between age 8 and teens. The prevalence of Jansky–Bielschowsky disease is unknown; however, NCL collectively affects an estimated 1 in 100,000 individuals worldwide. Jansky–Bielschowsky disease is related to late-infantile Batten disease and LINCL, and is under the umbrella of neuronal ceroid lipofuscinosis.
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.
Schindler disease, also known as Kanzaki disease and alpha-N-acetylgalactosaminidase deficiency, is a rare disease found in humans. This lysosomal storage disorder is caused by a deficiency in the enzyme alpha-NAGA (alpha-N-acetylgalactosaminidase), attributable to mutations in the NAGA gene on chromosome 22, which leads to excessive lysosomal accumulation of glycoproteins. A deficiency of the alpha-NAGA enzyme leads to an accumulation of glycosphingolipids throughout the body. This accumulation of sugars gives rise to the clinical features associated with this disorder. Schindler disease is an autosomal recessive disorder, meaning that one must inherit an abnormal allele from both parents in order to have the disease.
Galactosidase alpha is an enzyme that in humans is encoded by the GLA gene.
In molecular biology, glycoside hydrolase family 29 is a family of glycoside hydrolases.
Autophagic vacuolar myopathy (AVM) consists of multiple rare genetic disorders with common histological and pathological features on muscle biopsy. The features highlighted are vacuolar membranes of the autophagic vacuoles having sarcolemmal characteristics and an excess of autophagic vacuoles. There are currently five types of AVM identified. The signs and symptoms become more severe over the course of the disease. It begins with an inability to pick up small objects and progresses to difficulty in walking. The age of onset varies from early childhood to late adulthood, affecting people of all ages.
Velmanase alfa, sold under the brand name Lamzede, is a medication used for the treatment of alpha-mannosidosis. Velmanase alfa is a recombinant human lysosomal alpha-mannosidase.
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