Alkaptonuria
Homogentisate 1,2-Dioxygenase
Ochronosis
Homogentisic Acid
4-Hydroxyphenylpyruvate Dioxygenase
Facial Dermatoses
Dioxygenases
Hyperpigmentation
Scleral Diseases
Joint Diseases
Oxygenases
Encyclopedias as Topic
Phenylalanine
Resorcinols
Analysis of alkaptonuria (AKU) mutations and polymorphisms reveals that the CCC sequence motif is a mutational hot spot in the homogentisate 1,2 dioxygenase gene (HGO). (1/39)
We recently showed that alkaptonuria (AKU) is caused by loss-of-function mutations in the homogentisate 1,2 dioxygenase gene (HGO). Herein we describe haplotype and mutational analyses of HGO in seven new AKU pedigrees. These analyses identified two novel single-nucleotide polymorphisms (INV4+31A-->G and INV11+18A-->G) and six novel AKU mutations (INV1-1G-->A, W60G, Y62C, A122D, P230T, and D291E), which further illustrates the remarkable allelic heterogeneity found in AKU. Reexamination of all 29 mutations and polymorphisms thus far described in HGO shows that these nucleotide changes are not randomly distributed; the CCC sequence motif and its inverted complement, GGG, are preferentially mutated. These analyses also demonstrated that the nucleotide substitutions in HGO do not involve CpG dinucleotides, which illustrates important differences between HGO and other genes for the occurrence of mutation at specific short-sequence motifs. Because the CCC sequence motifs comprise a significant proportion (34.5%) of all mutated bases that have been observed in HGO, we conclude that the CCC triplet is a mutational hot spot in HGO. (+info)Allelic heterogeneity of alkaptonuria in Central Europe. (2/39)
Defects of the homogentisate 1,2 dioxygenase (HGO; E.C. No. 1.13.11.5) have been identified as the molecular cause of alkaptonuria in humans (AKU) and the aku mouse. Here, we report on the genetic basis of 30 AKU patients from Central Europe. In addition to five mutations described previously, we have detected five novel HGO mutations. Recombinant expression of mutated HGO enzymes in E. coli demonstrates the inactivating effect of three of these mutations. A genetic epidemiologic study in Slovakia, the country with the highest incidence of alkaptonuria, demonstrates that two recurrent mutations (c.183-1G > A and Glyl61Arg) are found on more than 50% of AKU chromosomes. An analysis of the allelic association with intragenic DNA markers and of the geographic origins of the AKU chromosomes suggests that several independent founders have contributed to the gene pool, and that subsequent genetic isolation is likely to be responsible for the high prevalence of alkaptonuria in Slovakia. (+info)Mutational analysis of the HGO gene in Finnish alkaptonuria patients. (3/39)
Alkaptonuria (AKU), the prototypic inborn error of metabolism, has recently been shown to be caused by loss of function mutations in the homogentisate-1,2-dioxygenase gene (HGO). So far 17 mutations have been characterised in AKU patients of different ethnic origin. We describe three novel mutations (R58fs, R330S, and H371R) and one common AKU mutation (M368V), detected by mutational and polymorphism analysis of the HGO gene in five Finnish AKU pedigrees. The three novel AKU mutations are most likely specific for the Finnish population and have originated recently. (+info)Structural and functional analysis of mutations in alkaptonuria. (4/39)
Alkaptonuria (AKU), the prototypic inborn error of metabolism, was the first human disease to be interpreted as a Mendelian trait by Garrod and Bateson at the beginning of last century. AKU results from impaired function of homogentisate dioxygenase (HGO), an enzyme required for the catabolism of phenylalanine and tyrosine. With the novel 7 AKU and 22 fungal mutations reported here, a total of 84 mutations impairing this enzyme have been found in the HGO gene from humans and model organisms. Forty-three of these mutations result in single amino acid substitutions. This mutational information is analysed here in the context of the HGO structure and function using kinetic assays performed using purified AKU mutant enzymes and the crystal structure of human HGO. HGO is a topologically complex structure which assembles as a functional hexamer arranged as a dimer of trimers. We show how the intricate pattern of intra- and inter-subunit interactions and the extensive surfaces required for subunit folding and association of this oligomeric enzyme can be inactivated at multiple levels by single-residue substitutions. This explains, in part, the predominance of missense mutations (67%) in AKU. (+info)High frequency of alkaptonuria in Slovakia: evidence for the appearance of multiple mutations in HGO involving different mutational hot spots. (5/39)
Alkaptonuria (AKU) is an autosomal recessive disorder caused by the deficiency of homogentisate 1,2 dioxygenase (HGO) activity. AKU shows a very low prevalence (1:100,000-250,000) in most ethnic groups. One notable exception is in Slovakia, where the incidence of AKU rises to 1:19,000. This high incidence is difficult to explain by a classical founder effect, because as many as 10 different AKU mutations have been identified in this relatively small country. We have determined the allelic associations of 11 HGO intragenic polymorphisms for 44 AKU chromosomes from 20 Slovak pedigrees. These data were compared to the HGO haplotype data available in our laboratory for >80 AKU chromosomes from different European and non-European countries. The results show that common European AKU chromosomes have had only a marginal contribution to the Slovak AKU gene pool. Six of the ten Slovak AKU mutations, including the prevalent G152fs, G161R, G270R, and P370fs mutations, most likely originated in Slovakia. Data available for 17 Slovak AKU pedigrees indicate that most of the AKU chromosomes have their origins in a single very small region in the Carpathian mountains, in the northwestern part of the country. Since all six Slovak AKU mutations are associated with HGO mutational hot spots, we suggest that an increased mutation rate at the HGO gene is responsible for the clustering of AKU mutations in such a small geographical region. (+info)Screening for inherited metabolic disease in Wales using urine-impregnated filter paper. (6/39)
Urine specimens from 135 295 infants have been collected on filter papers and tested for 7 abnormal urinary constituents using spot tests and paper chromatography. The method has detected 5 infants with phenylketonuria, 4 with histidinaemia, 5 with cystinuria, 5 with diabetes mellitus, and one with alcaptonuria. Transient abnormalities such as tyrosyluria, generalized aminoaciduria, cystinuria, and glycosuria have been noted. 2 phenylketonuric infants failed to excrete a detectable quantity of o-hydroxyphenlacetic acid at the time of testing. The findings show that the detection of this compound in urine is an unreliable method of screening for phenylketonuria. (+info)Natural history of alkaptonuria. (7/39)
BACKGROUND: Alkaptonuria, caused by mutations in the HGO gene and a deficiency of homogentisate 1,2-dioxygenase, results in an accumulation of homogentisic acid (HGA), ochronosis, and destruction of connective tissue. There is no effective therapy for this disorder, although nitisinone inhibits the enzyme that produces HGA. We performed a study to delineate the natural history of alkaptonuria. METHODS: We evaluated 58 patients with alkaptonuria (age range, 4 to 80 years), using clinical, radiographic, biochemical, and molecular methods. A radiographic scoring system was devised to assess the severity of spinal and joint damage. Two patients were treated with nitisinone for 10 and 9 days, respectively. RESULTS: Life-table analyses showed that joint replacement was performed at a mean age of 55 years and that renal stones developed at 64 years, cardiac-valve involvement at 54 years, and coronary-artery calcification at 59 years. Linear regression analysis indicated that the radiographic score for the severity of disease began increasing after the age of 30 years, with a more rapid increase in men than in women. Twenty-three new HGO mutations were identified. In a 51-year-old woman, urinary HGA excretion fell from 2.9 to 0.13 g per day after a 10-day course of nitisinone (7 days at a dose of 0.7 mg per day and 3 days at 2.8 mg per day). In a 59-year-old woman, urinary HGA fell from 6.4 g to 1.7 g per day after nine days of treatment with nitisinone (0.7 mg per day). Plasma tyrosine levels in these patients rose from approximately 1.1 mg per deciliter (60 micromol per liter) in both to approximately 12.8 mg per deciliter (700 micromol per liter) and 23.6 mg per deciliter (1300 micromol per liter), respectively, with no clinical signs or symptoms. CONCLUSIONS: The reported data on the natural history of alkaptonuria provide a basis for the evaluation of long-term therapies. Although nitisinone can reduce HGA production in humans with homogentisate 1,2-dioxygenase deficiency, the long-term safety and efficacy of this treatment require further evaluation. (+info)Spontaneous tendon ruptures in alkaptonuria. (8/39)
Ochronosis, the musculoskeletal manifestation of alkaptonuria, is known to lead to degenerative changes of the spine and weight-bearing joints. Symptoms related to degeneration of tendons or ligaments with spontaneous ruptures have not previously been reported. Three patients are described with four spontaneous ruptures of either the patellar tendon or tendo Achillis as the first symptom of alkaptonuria. (+info)Alkaptonuria is a rare inherited metabolic disorder characterized by the accumulation of homogentisic acid in various tissues and body fluids due to a deficiency in the enzyme homogentisate 1,2-dioxygenase. This enzyme deficiency leads to an inability to break down tyrosine and phenylalanine amino acids properly, causing their byproduct, homogentisic acid, to build up in the body.
The accumulation of homogentisic acid can result in several clinical manifestations:
1. Dark urine: Homogentisic acid oxidizes and turns dark brown or black when exposed to air, giving the condition its name "alkaptonuria," derived from Greek words 'alos' (meaning 'strange') and 'kapto' (meaning 'I become black').
2. Arthritis: Over time, homogentisic acid deposits in connective tissues, particularly cartilage, causing damage and leading to a form of arthritis called ochronosis. This can result in stiffness, pain, and limited mobility in affected joints.
3. Heart problems: Homogentisic acid accumulation in heart valves may lead to thickening and calcification, potentially resulting in heart disease and valve dysfunction.
4. Kidney stones: The accumulation of homogentisic acid can form kidney stones, which can cause pain and potential kidney damage if they become lodged in the urinary tract.
There is no cure for alkaptonuria; however, treatment aims to manage symptoms and slow disease progression. A low-protein diet may help reduce tyrosine and phenylalanine intake, while increased hydration can help prevent kidney stone formation. Nitisinone, a medication that inhibits the production of homogentisic acid, has shown promise in managing alkaptonuria symptoms. Regular monitoring and early intervention are crucial to minimize complications associated with this rare condition.
Homogentisate 1,2-dioxygenase (HGD) is an enzyme that plays a crucial role in the catabolism of tyrosine, an aromatic amino acid. This enzyme is involved in the third step of the tyrosine degradation pathway, also known as the tyrosine breakdown or catabolic pathway.
The homogentisate 1,2-dioxygenase enzyme catalyzes the conversion of homogentisic acid (HGA) into maleylacetoacetic acid. This reaction involves the cleavage of the aromatic ring of HGA and the introduction of oxygen, hence the name 'dioxygenase.' The reaction can be summarized as follows:
Homogentisate + O2 → Maleylacetoacetate
Deficiency or dysfunction in homogentisate 1,2-dioxygenase leads to a rare genetic disorder called alkaptonuria. In this condition, the body cannot break down tyrosine properly, resulting in an accumulation of HGA and its oxidation product, alkapton, which can cause damage to connective tissues and joints over time.
Ochronosis is a medical condition characterized by the accumulation of a dark pigment called homogentisic acid in various connective tissues, such as the skin, tendons, and cartilage. This accumulation results in a bluish-black or grayish discoloration of the affected tissues, which can lead to stiffness, pain, and limited mobility. Ochronosis is often associated with alkaptonuria, a rare inherited metabolic disorder that affects the breakdown of certain amino acids. However, it can also occur as a result of exposure to certain chemicals or medications.
Homogentisic acid is not a medical condition, but rather an organic compound that plays a role in certain metabolic processes. It is a breakdown product of the amino acid tyrosine, and is normally further metabolized by the enzyme homogentisate 1,2-dioxygenase.
In some individuals, a genetic mutation can result in a deficiency of this enzyme, leading to a condition called alkaptonuria. In alkaptonuria, homogentisic acid accumulates in the body and can cause damage to connective tissues, joints, and other organs over time. Symptoms may include dark urine, arthritis, and pigmentation of the ears and eyes. However, it is important to note that alkaptonuria is a rare condition, affecting only about 1 in 250,000 people worldwide.
4-Hydroxyphenylpyruvate dioxygenase (HPPD) is an enzyme that is involved in the catabolism of aromatic amino acids such as tyrosine. The gene for HPPD is located on human chromosome 12q24.11.
The HPPD enzyme catalyzes the conversion of 4-hydroxyphenylpyruvate to homogentisate, which is then further metabolized in the catabolic pathway leading to fumarate and acetoacetate. Deficiencies in HPPD activity have been associated with certain genetic disorders such as tyrosinemia type III, which can result in neurological symptoms and developmental delays.
In addition to its role in normal metabolism, HPPD has also been identified as a target for herbicides that inhibit the enzyme's activity, leading to the accumulation of 4-hydroxyphenylpyruvate and other toxic intermediates that can disrupt plant growth and development.
Facial dermatoses refer to various skin conditions that affect the face. These can include a wide range of disorders, such as:
1. Acne vulgaris: A common skin condition characterized by the formation of comedones (blackheads and whiteheads) and inflammatory papules, pustules, and nodules. It primarily affects the face, neck, chest, and back.
2. Rosacea: A chronic skin condition that causes redness, flushing, and visible blood vessels on the face, along with bumps or pimples and sometimes eye irritation.
3. Seborrheic dermatitis: A common inflammatory skin disorder that causes a red, itchy, and flaky rash, often on the scalp, face, and eyebrows. It can also affect other oily areas of the body, like the sides of the nose and behind the ears.
4. Atopic dermatitis (eczema): A chronic inflammatory skin condition that causes red, itchy, and scaly patches on the skin. While it can occur anywhere on the body, it frequently affects the face, especially in infants and young children.
5. Psoriasis: An autoimmune disorder that results in thick, scaly, silvery, or red patches on the skin. It can affect any part of the body, including the face.
6. Contact dermatitis: A skin reaction caused by direct contact with an allergen or irritant, resulting in redness, itching, and inflammation. The face can be affected when allergens or irritants come into contact with the skin through cosmetics, skincare products, or other substances.
7. Lupus erythematosus: An autoimmune disorder that can cause a butterfly-shaped rash on the cheeks and nose, along with other symptoms like joint pain, fatigue, and photosensitivity.
8. Perioral dermatitis: A inflammatory skin condition that causes redness, small bumps, and dryness around the mouth, often mistaken for acne. It can also affect the skin around the nose and eyes.
9. Vitiligo: An autoimmune disorder that results in the loss of pigmentation in patches of skin, which can occur on the face and other parts of the body.
10. Tinea faciei: A fungal infection that affects the facial skin, causing red, scaly, or itchy patches. It is also known as ringworm of the face.
These are just a few examples of skin conditions that can affect the face. If you experience any unusual symptoms or changes in your skin, it's essential to consult a dermatologist for proper diagnosis and treatment.
Cyclohexanones are organic compounds that consist of a cyclohexane ring (a six-carbon saturated ring) with a ketone functional group (-CO-) attached to it. The general structure is C6H11CO. They can be found in various natural sources, including essential oils and certain plants, but many cyclohexanones are also synthesized for use in the chemical industry.
Cyclohexanones are important intermediates in the production of various chemicals, such as nylon and other synthetic fibers, resins, and perfumes. One of the most common cyclohexanones is cyclohexanone itself, which is a colorless liquid with an odor reminiscent of peppermint or acetone. It is used in the production of adipic acid, a precursor to nylon.
Like other ketones, cyclohexanones can undergo various chemical reactions, such as reduction, oxidation, and condensation. However, due to the cyclic structure of cyclohexanones, they also exhibit unique reactivity patterns that are exploited in organic synthesis.
Dioxygenases are a class of enzymes that catalyze the incorporation of both atoms of molecular oxygen (O2) into their substrates. They are classified based on the type of reaction they catalyze and the number of iron atoms in their active site. The two main types of dioxygenases are:
1. Intradiol dioxygenases: These enzymes cleave an aromatic ring by inserting both atoms of O2 into a single bond between two carbon atoms, leading to the formation of an unsaturated diol (catechol) intermediate and the release of CO2. They contain a non-heme iron(III) center in their active site.
An example of intradiol dioxygenase is catechol 1,2-dioxygenase, which catalyzes the conversion of catechol to muconic acid.
2. Extradiol dioxygenases: These enzymes cleave an aromatic ring by inserting one atom of O2 at a position adjacent to the hydroxyl group and the other atom at a more distant position, leading to the formation of an unsaturated lactone or cyclic ether intermediate. They contain a non-heme iron(II) center in their active site.
An example of extradiol dioxygenase is homogentisate 1,2-dioxygenase, which catalyzes the conversion of homogentisate to maleylacetoacetate in the tyrosine degradation pathway.
Dioxygenases play important roles in various biological processes, including the metabolism of aromatic compounds, the biosynthesis of hormones and signaling molecules, and the detoxification of xenobiotics.
Hyperpigmentation is a medical term that refers to the darkening of skin areas due to an increase in melanin, the pigment that provides color to our skin. This condition can affect people of all races and ethnicities, but it's more noticeable in those with lighter skin tones.
Hyperpigmentation can be caused by various factors, including excessive sun exposure, hormonal changes (such as during pregnancy), inflammation, certain medications, and underlying medical conditions like Addison's disease or hemochromatosis. It can also result from skin injuries, such as cuts, burns, or acne, which leave dark spots known as post-inflammatory hyperpigmentation.
There are several types of hyperpigmentation, including:
1. Melasma: This is a common form of hyperpigmentation that typically appears as symmetrical, blotchy patches on the face, particularly the forehead, cheeks, and upper lip. It's often triggered by hormonal changes, such as those experienced during pregnancy or while taking birth control pills.
2. Solar lentigos (age spots or liver spots): These are small, darkened areas of skin that appear due to prolonged sun exposure over time. They typically occur on the face, hands, arms, and decolletage.
3. Post-inflammatory hyperpigmentation: This type of hyperpigmentation occurs when an injury or inflammation heals, leaving behind a darkened area of skin. It's more common in people with darker skin tones.
Treatment for hyperpigmentation depends on the underlying cause and may include topical creams, chemical peels, laser therapy, or microdermabrasion. Preventing further sun damage is crucial to managing hyperpigmentation, so wearing sunscreen with a high SPF and protective clothing is recommended.
Nitrobenzoates are a type of organic compound that consists of a benzoate group (a carboxylate derived from benzoic acid) with a nitro group (-NO2) attached to the benzene ring. They are often used in chemical synthesis and have also been studied for their potential medicinal properties, such as their antimicrobial and anti-inflammatory effects. However, they are not commonly used in modern medicine as therapeutic agents.
Scleral diseases refer to conditions that affect the sclera, which is the tough, white outer coating of the eye. The sclera helps to maintain the shape of the eye and provides protection for the internal structures. Scleral diseases can cause inflammation, degeneration, or thinning of the sclera, leading to potential vision loss or other complications. Some examples of scleral diseases include:
1. Scleritis: an inflammatory condition that causes pain, redness, and sensitivity in the affected area of the sclera. It can be associated with autoimmune disorders, infections, or trauma.
2. Episcleritis: a less severe form of inflammation that affects only the episclera, a thin layer of tissue overlying the sclera. Symptoms include redness and mild discomfort but typically no pain.
3. Pinguecula: a yellowish, raised deposit of protein and fat that forms on the conjunctiva, the clear membrane covering the sclera. While not a disease itself, a pinguecula can cause irritation or discomfort and may progress to a more severe condition called a pterygium.
4. Pterygium: a fleshy growth that extends from the conjunctiva onto the cornea, potentially obstructing vision. It is often associated with prolonged sun exposure and can be removed surgically if it becomes problematic.
5. Scleral thinning or melting: a rare but serious condition where the sclera degenerates or liquefies, leading to potential perforation of the eye. This can occur due to autoimmune disorders, infections, or as a complication of certain surgical procedures.
6. Ocular histoplasmosis syndrome (OHS): a condition caused by the Histoplasma capsulatum fungus, which can lead to scarring and vision loss if it involves the macula, the central part of the retina responsible for sharp, detailed vision.
It is essential to consult an ophthalmologist or eye care professional if you experience any symptoms related to scleral diseases to receive proper diagnosis and treatment.
Joint diseases is a broad term that refers to various conditions affecting the joints, including but not limited to:
1. Osteoarthritis (OA): A degenerative joint disease characterized by the breakdown of cartilage and underlying bone, leading to pain, stiffness, and potential loss of function.
2. Rheumatoid Arthritis (RA): An autoimmune disorder causing inflammation in the synovial membrane lining the joints, resulting in swelling, pain, and joint damage if left untreated.
3. Infectious Arthritis: Joint inflammation caused by bacterial, viral, or fungal infections that spread through the bloodstream or directly enter the joint space.
4. Gout: A type of arthritis resulting from the buildup of uric acid crystals in the joints, typically affecting the big toe and characterized by sudden attacks of severe pain, redness, and swelling.
5. Psoriatic Arthritis (PsA): An inflammatory joint disease associated with psoriasis, causing symptoms such as pain, stiffness, and swelling in the joints and surrounding tissues.
6. Juvenile Idiopathic Arthritis (JIA): A group of chronic arthritis conditions affecting children, characterized by joint inflammation, pain, and stiffness.
7. Ankylosing Spondylitis: A form of arthritis primarily affecting the spine, causing inflammation, pain, and potential fusion of spinal vertebrae.
8. Bursitis: Inflammation of the fluid-filled sacs (bursae) that cushion joints, leading to pain and swelling.
9. Tendinitis: Inflammation or degeneration of tendons, which connect muscles to bones, often resulting in pain and stiffness near joints.
These conditions can impact the function and mobility of affected joints, causing discomfort and limiting daily activities. Proper diagnosis and treatment are essential for managing joint diseases and preserving joint health.
Oxygenases are a class of enzymes that catalyze the incorporation of molecular oxygen (O2) into their substrates. They play crucial roles in various biological processes, including the biosynthesis of many natural products, as well as the detoxification and degradation of xenobiotics (foreign substances).
There are two main types of oxygenases: monooxygenases and dioxygenases. Monooxygenases introduce one atom of molecular oxygen into a substrate while reducing the other to water. An example of this type of enzyme is cytochrome P450, which is involved in drug metabolism and steroid hormone synthesis. Dioxygenases, on the other hand, incorporate both atoms of molecular oxygen into their substrates, often leading to the formation of new carbon-carbon bonds or the cleavage of existing ones.
It's important to note that while oxygenases are essential for many life-sustaining processes, they can also contribute to the production of harmful reactive oxygen species (ROS) during normal cellular metabolism. An imbalance in ROS levels can lead to oxidative stress and damage to cells and tissues, which has been linked to various diseases such as cancer, neurodegeneration, and cardiovascular disease.
An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.
Phenylalanine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through diet or supplementation. It's one of the building blocks of proteins and is necessary for the production of various molecules in the body, such as neurotransmitters (chemical messengers in the brain).
Phenylalanine has two forms: L-phenylalanine and D-phenylalanine. L-phenylalanine is the form found in proteins and is used by the body for protein synthesis, while D-phenylalanine has limited use in humans and is not involved in protein synthesis.
Individuals with a rare genetic disorder called phenylketonuria (PKU) must follow a low-phenylalanine diet or take special medical foods because they are unable to metabolize phenylalanine properly, leading to its buildup in the body and potential neurological damage.
Ear cartilage, also known as auricular cartilage, refers to the flexible connective tissue that makes up the structural framework of the external ear or pinna. The ear cartilage provides support and shape to the ear, helping to direct sound waves into the ear canal and towards the eardrum.
The ear cartilage is composed of type II collagen fibers and proteoglycans, which give it its flexibility and resiliency. It is covered by a thin layer of skin on both sides and contains no bones. Instead, the ear cartilage is shaped and maintained by the surrounding muscles and connective tissue.
There are three main parts of the ear cartilage: the helix, the antihelix, and the tragus. The helix is the outer rim of the ear, while the antihelix is the curved ridge that runs parallel to the helix. The tragus is the small piece of cartilage that projects from the front of the ear canal.
Ear cartilage can be affected by various conditions, including trauma, infection, and degenerative changes associated with aging. In some cases, surgical procedures may be required to reshape or reconstruct damaged ear cartilage.
Resorcinols are a type of chemical compound that contain a resorcinol moiety, which is made up of a benzene ring with two hydroxyl groups in the ortho position. In medicine, resorcinol and its derivatives have been used for various purposes, including as antiseptics, antibacterials, and intermediates in the synthesis of other pharmaceuticals.
Resorcinol itself has some medicinal properties, such as being able to reduce pain and inflammation, and it has been used topically to treat conditions like eczema, psoriasis, and acne. However, resorcinol can also be toxic in large amounts, so it must be used with caution.
It's important to note that while resorcinol is a chemical compound, the term "resorcinols" may also refer to a group of related compounds that contain the resorcinol moiety. These compounds can have different medicinal properties and uses depending on their specific structure and function.
Hydroquinones are a type of chemical compound that belong to the group of phenols. In a medical context, hydroquinones are often used as topical agents for skin lightening and the treatment of hyperpigmentation disorders such as melasma, age spots, and freckles. They work by inhibiting the enzyme tyrosinase, which is necessary for the production of melanin, the pigment that gives skin its color.
It's important to note that hydroquinones can have side effects, including skin irritation, redness, and contact dermatitis. Prolonged use or high concentrations may also cause ochronosis, a condition characterized by blue-black discoloration of the skin. Therefore, they should be used under the supervision of a healthcare provider and for limited periods of time.
Alkaptonuria
List of OMIM disorder codes
Dioxygenase
Homogentisic acid
Archibald Garrod
Osteoarthritis
4-Hydroxyphenylpyruvate dioxygenase
Allelic heterogeneity
Ochronosis
Tyrosinemia
Human tooth
Garrod's tetrad
Homogentisate 1,2-dioxygenase
Paul Fürbringer
Nitisinone
Maleylacetoacetate isomerase
William A. Gahl
Urinalysis
Tyrosine
Pentosuria
Inborn errors of metabolism
Tooth whitening
Urobilin
GSTZ1
List of skin conditions
Timeline of the history of genetics
One gene-one enzyme hypothesis
Chromosome 3
List of systemic diseases with ocular manifestations
Mendelian traits in humans
Alkaptonuria - Wikipedia
Alkaptonuria: MedlinePlus Genetics
Ochronosis and Alkaptonuria: Practice Essentials, Pathophysiology, Epidemiology
Alkaptonuria (Black Urine Disease): Background, Pathophysiology, Epidemiology
Ochronosis and calcification in the mediastinal mass of a patient with alkaptonuria | Journal of Clinical Pathology
Alkaptonuria Drugs Market - Request for Custom Research Report
Identification of alkaptonuria in the general population:a United Kingdom experience describing the challenges, possible...
Alkaptonuria: Video, Anatomy, Definition & Function | Osmosis
Alkaptonuria - wikidoc
Alkaptonuria Differential Diagnoses
Alkaptonuria: Background, Pathophysiology, Epidemiology
Alkaptonuria - Causes, Symptoms, Diagnosis, Treatment and Prognosis
The National Alkaptonuria Centre - The AKU Society
M hobby motility fall needed; alkaptonuria; heal. - TELEMIX
Alkaptonuria, Hereditary Ochronosis, Homogentisic Acid Oxidase deficiency - Eurofins Genoma
Treatment of Alkaptonuria | American Board of Internal Medicine Certification | Knowmedge
The effect of nitisinone on homogentisic acid and tyrosine: a two-year survey of patients attending the National Alkaptonuria...
Comparative proteomics in alkaptonuria provides insights into inflammation and oxidative stress
Arthroplasty - Glossary Definition
OMIA:001243-9601: Alkaptonuria in Pongo abelii (Sumatran orangutan) - OMIA - Online Mendelian Inheritance in...
"Musculoskeletal manifestations in alkaptonuria: A cross-sectional stud" by Aysha Habib Khan, Bushra Afroze et al.
Amino Acid Metabolism Disorders: MedlinePlus
SONIA 1&2 Impact Case Study | NIHR
Identification of the mutation in the alkaptonuria mouse model. Mutations in brief no. 216. Online.<...
MedlinePlus - Search Results for: NITISINONE
Orfadin | European Medicines Agency
Micrognathia: Causes, Treatments, and When to Seek Help
Publications - Joanna Klubo-Gwiezdzinska, M.D., Ph.D., M.H.Sc., Lasker Tenure Track Investigator - NIDDK
Ochronosis7
- Endogenous ochronosis (alkaptonuria). (medlineplus.gov)
- Ochronosis is the bluish-black discoloration of certain tissues, such as the ear cartilage and the ocular tissue, seen with alkaptonuria , a metabolic disorder. (medscape.com)
- Alkaptonuria is a rare genetic disorder in which there is a deficiency of the enzyme homogentisic acid oxidase, resulting in the accumulation of homogentisic acid and a characteristic blue-black discoloration of the skin and cartilage, called ochronosis. (medscape.com)
- Ochronosis was defined by Virchow who histologically described the connective tissue in alkaptonuria, given the cartilage's ochre, or yellow, hue under the microscope. (medscape.com)
- Alkaptonuria ( black urine disease , alcaptonuria or ochronosis ) is a rare inherited genetic disorder of tyrosine metabolism. (wikidoc.org)
- Biochemical, pathological and clinical aspects of alcaptonuria, ochronosis and ochronotic arthropathy: review of the world literature (1584-1962). (medscape.com)
- Endogenous ochronosis (EO) or alkaptonuria is an inherited autosomal recessive disease caused by the insufficiency of the enzyme homogentisic acid dioxygenase. (cdlib.org)
Autosomal4
- Alkaptonuria is a rare autosomal recessive metabolic disorder caused by deficiency of homogentisic acid oxidase, the only enzyme capable of catabolizing homogentisic acid (HGA). (medscape.com)
- As Garrod suggested, alkaptonuria is an autosomal recessive genetic trait, although an autosomal dominant transmission pattern in 3 generations in a nonconsanguineous family has been reported. (medscape.com)
- Alkaptonuria (AKU) is a rare autosomal recessive condition with a prevalence of 1 in 250 000-1 000 000 1 caused by the deficiency of homogentisate 1,2 dioxygenase, the enzyme responsible for breaking down homogentisic acid (HGA). (bmj.com)
- Background Alkaptonuria is a rare, debilitating autosomal recessive disorder affecting tyrosine metabolism. (qxmd.com)
National Alkaptonuria Centre4
- The Robert Gregory National Alkaptonuria Centre exists to change this. (akusociety.org)
- If you would like to know more about the National Alkaptonuria Centre, please contact Lesley Harrison by emailing her at le****@ak********.org or giving her a call on 07586759028 . (akusociety.org)
- The effect of nitisinone on homogentisic acid and tyrosine: a two-year survey of patients attending the National Alkaptonuria Centre, Liverpool. (qxmd.com)
- The National Alkaptonuria Centre in Liverpool has been using 2 mg nitisinone (NTBC) off-license for all patients in the United Kingdom with alkaptonuria and monitoring the tyrosine metabolite profiles. (qxmd.com)
Inborn errors of1
- The Croonian lectures on inborn errors of metabolism: lecture II: alkaptonuria. (wikidoc.org)
Nitisinone5
- Ranganath et al have shown that nitisinone 2 mg daily and 10 mg daily are beneficial in patients with alkaptonuria, with 10 mg displaying a greater decrease in HGA. (medscape.com)
- Nitisinone 10 mg was approved by the European Medicines Agency for adults with alkaptonuria in 2020. (medscape.com)
- Use of nitisinone in patients with alkaptonuria. (medscape.com)
- Long-term study of nitisinone to treat alkaptonuria. (nih.gov)
- Tony's experience in drug development includes significant contributions to the repurposing of nitisinone for the treatment of alkaptonuria (AKU), a rare genetic disease affecting Nick's two sons. (onenucleus.com)
Homogentisic acid8
- In alkaptonuria, the HGD enzyme cannot metabolize the homogentisic acid (generated from tyrosine) into 4-maleylacetoacetate, and homogentisic acid levels in the blood are 100-fold higher than would normally be expected, despite the fact that a substantial amount is eliminated into the urine by the kidneys. (wikipedia.org)
- If the diagnosis of alkaptonuria is suspected, it can be confirmed or excluded by collecting urine for 24 hours and determining the amount of homogentisic acid by means of chromatography. (wikipedia.org)
- Alkaptonuria is a rare inherited disorder in which a deficiency of an enzyme called homogentisate 1,2 dioxygenase - HGD, results in the accumulation of homogentisic acid in connective tissues . (osmosis.org)
- A distinctive characteristic of alkaptonuria is that ear wax exposed to air turns red or black (depending on diet) after several hours because of the accumulation of homogentisic acid. (wikidoc.org)
- Homogentisic acid is completely absent from both urine and blood plasma if the individual does not have Alcaptonuria. (hxbenefit.com)
- Alkaptonuria (AKU) is an ultra-rare inborn error of metabolism associated with a defective catabolism of phenylalanine and tyrosine leading to increased systemic levels of homogentisic acid (HGA). (unisi.it)
- Urine organic acid analysis showed elevation in homogentisic acid consistent with alkaptonuria. (omia.org)
- Alkaptonuria patients were diagnosed based on the homogentisic acid peak in urine and their demographics and clinical data collected from to 2013 to 2019. (aku.edu)
Genetics2
- Zatkova A. An update on molecular genetics of Alkaptonuria (AKU). (medlineplus.gov)
- This study aimed to determine the patient characteristics and clinical presentation of Alkaptonuria cases reported by the Biochemical Genetics Lab.An observational study was conducted at the Biochemical Genetics Lab. (aku.edu)
Urine7
- citation needed] Patients with alkaptonuria are asymptomatic as children or young adults, but their urine may turn brown or even inky black if collected and left exposed to open air. (wikipedia.org)
- Alkaptonuria is an inherited condition that causes urine to turn black when exposed to air. (medlineplus.gov)
- Alkaptonuria, also called black urine disease, alcaptonuria, and black bone disease, is one of 4 disorders originally defined as an inborn error of metabolism by Archibald Garrod in his Croonian Lectures of 1902. (medscape.com)
- People with alkaptonuria can also present with vision and hearing problems, and have dark urine. (osmosis.org)
- Peker E, Yonden Z, Sogut S. From darkening urine to early diagnosis of alkaptonuria. (medscape.com)
- Alkaptonuria is a genetic disorder in which the urine of the patient turns black once exposed to air. (hxbenefit.com)
- 8. Alkaptonuria is a rare condition in which a person's urine turns a dark brownish-black color when exposed to air. (listverse.com)
Coronary artery1
- Vavuranakis M, Triantafillidi H, Stefanadis C, Toutouzas P. Aortic stenosis and coronary artery disease caused by alkaptonuria, a rare genetic metabolic syndrome. (medscape.com)
Patients8
- Patients with alkaptonuria should be informed that they will have a normal life span, despite pigmentary alterations and arthritis that materialize in mid life. (medscape.com)
- Identification of 11 Novel Homogentisate 1,2 Dioxygenase Variants in Alkaptonuria Patients and Establishment of a Novel LOVD-Based HGD Mutation Database. (medscape.com)
- The success of dietary protein restriction in alkaptonuria patients is age-dependent. (medscape.com)
- Although parents of Alcaptonuria patients are carriers of the mutated gene, they do not usually develop the symptoms themselves. (hxbenefit.com)
- Methods Patients with confirmed alkaptonuria are commenced on 2 mg dose (alternative days) of NTBC for three months with daily dose thereafter. (qxmd.com)
- Alkaptonuria (AKU), also known as black bone disease, is so rare that currently there are only roughly 65 patients in the UK that are known to have it. (nihr.ac.uk)
- These studies are absolutely vital in understanding more about how best to treat patients living with Alkaptonuria. (nihr.ac.uk)
- Assessment of Thyroid Function in Patients With Alkaptonuria. (nih.gov)
Diagnosis1
- Early diagnosis of co-existent ß-thalassemia and alkaptonuria. (medscape.com)
Gene2
- In people with alkaptonuria, both copies of the gene contain abnormalities that mean that the body cannot produce an adequately functioning enzyme. (wikipedia.org)
- Mutations in the HGD gene cause alkaptonuria. (medlineplus.gov)
Musculoskeletal2
- Musculoskeletal findings and disability in alkaptonuria. (medscape.com)
- Musculoskeletal manifestations in alkaptonuria: A cross-sectional stud" by Aysha Habib Khan, Bushra Afroze et al. (aku.edu)
Rare3
- This paper discusses strategies to identify individuals with the rare genetic disease alkaptonuria (AKU) within the general population. (lancs.ac.uk)
- The bluish-black sclera in his eyes is a rare disease called alkaptonuria. (rense.com)
- Archibald had verified that alkaptonuria was inherited by Mandeline rules and includes rare recessive mutation. (timetoast.com)
Biochemical2
- Alkaptonuria features a defect in the biochemical pathway by which phenylalanine and tyrosine are normally degraded into fumaric and acetoacetic acid. (medscape.com)
- Biochemical and molecular confirmation of alkaptonuria in a Sumatran orangutan (Pongo abelii). (omia.org)
Phenylketonuria2
- These include the fact that newborn screening for alkaptonuria is much less widely practiced than that for phenylketonuria . (medscape.com)
- Thus defects in this enzyme may lead to severe metabolic disorders including alkaptonuria, phenylketonuria and tyrosinaemia. (nih.gov)
Diseases1
- Alkaptonuria was one of the four diseases described by Sir Archibald Edward Garrod , as being the result of the accumulation of intermediates due to metabolic deficiencies. (wikidoc.org)
Mutation2
- Identification of the mutation in the alkaptonuria mouse model. (elsevierpure.com)
- Alkaptonuria (aku), an inborn error of metabolism caused by the loss of homogentisate 1,2-dioxygenase (HGD), has been described in a mouse model created by ethylnitrosourea mutagenesis but the mutation in these mice has not previously been identified. (elsevierpure.com)
Incidence2
- Alkaptonuria is more common in certain areas of Slovakia (where it has an incidence of about 1 in 19,000 people) and in the Dominican Republic. (medlineplus.gov)
- The incidence of alkaptonuria: a study in clinical individuality. (wikidoc.org)
Arthritis2
- People with alkaptonuria typically develop arthritis, particularly in the spine and large joints, beginning in early adulthood. (medlineplus.gov)
- In adulthood, but usually not before age forty, persons suffering from alkaptonuria develop progressive arthritis (especially of the spine), due to the long-term buildup of homogentisate in bones and cartilage. (wikidoc.org)
Adults1
- alkaptonuria (AKU) in adults. (europa.eu)
Black1
- The SONIA 1&2 studies investigated how best to treat Alkaptonuria (AKU), also known as black bone disease. (nihr.ac.uk)
People2
- Irregularities in the heart rhythm and heart failure affect a significant proportion of people with alkaptonuria (40% and 10%, respectively). (wikipedia.org)
- Many people diagnosed with alkaptonuria (AKU) have difficulty accessing efficient and effective care to treat their AKU. (akusociety.org)
Identification1
- Identification of alkaptonuria in the general population:a United Kingdom experience describing the challenges, possible solutions and persistent barriers. (lancs.ac.uk)
Disease1
- In 1902 the British physician, Archibald Garrod founded a disease named alkaptonuria. (timetoast.com)
Family1
- Three-generational alkaptonuria in a non-consanguineous family. (medscape.com)
History1
- Natural history of alkaptonuria. (medlineplus.gov)