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Adrenoleukodystrophy
Adrenoleukodystrophy (ALD) is a genetic disorder, disease linked to the X chromosome. It is a result of fatty acid buildup caused by failure of peroxisome#Metabolic functions, peroxisomal fatty acid beta oxidation which results in the accumulation of very long chain fatty acids in tissues throughout the body. The most severely affected tissues are the myelin in the central nervous system, the adrenal cortex, and the Leydig cells in the testes. The long chain fatty acid buildup causes damage to the myelin sheath of the neurons of the brain, resulting in seizures and hyperactivity. Other symptoms include problems in speaking, listening, and understanding verbal instructions. Clinically, ALD presents as a heterogeneous disorder, showing several distinct phenotypes, and no clear pattern of genotype–phenotype correlation. As an X-linked disorder, ALD presents more frequently and severely in males; however, approximately 80% of heterozygote females show some symptoms later in life. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABCD1
ABCD1 is a protein that transfers fatty acids into peroxisomes. Function The protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the ALD subfamily, which is involved in peroxisomal import of fatty acids and/or fatty acyl-CoAs in the organelle. All known peroxisomal ABC transporters are half transporters which require a partner half transporter molecule to form a functional homodimeric or heterodimeric transporter. This peroxisomal membrane protein is likely involved in the peroxisomal transport or catabolism of very long chain fatty acids. Clinical significance Defects in this gene have been identified as the underlying cause of adrenoleukodystrophy, an X-chromosome recessively inherited demyelinating disorder of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenomyeloneuropathy
Adrenomyeloneuropathy (AMN) is a rare hereditary neurodegenerative disorder that primarily affects the spinal cord and peripheral nerves, occurring in less than 1 in 40,000 people. It is characterised by progressive motor dysfunction and adrenal insufficiency. AMN is a form of X-linked adrenoleukodystrophy, a peroxisomal disorder caused by mutations in the ''ABCD1'' gene. Symptoms most commonly begin in a person's late twenties. AMN predominantly affects adult males but heterozygous females may develop symptoms later in life. Treatments mainly center around symptom-management. Symptoms Symptoms of AMN typically begin in adulthood, with the mean onset of symptoms for affected males occurring at 27.6 years of age. Common symptoms include: * Spastic paraparesis (progressive stiffness and weakness of the legs) * Ataxia (loss of coordination) * Neurogenic bladder and bowel dysfunction * Sexual dysfunction * Adrenocortical insufficiency, leading to fatigue, weight loss, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Chromosome
The X chromosome is one of the two sex chromosomes in many organisms, including mammals, and is found in both males and females. It is a part of the XY sex-determination system and XO sex-determination system. The X chromosome was named for its unique properties by early researchers, which resulted in the naming of its counterpart Y chromosome, for the next letter in the alphabet, following its subsequent discovery. Discovery It was first noted that the X chromosome was special in 1890 by Hermann Henking in Leipzig. Henking was studying the testicles of '' Pyrrhocoris'' and noticed that one chromosome did not take part in meiosis. Chromosomes are so named because of their ability to take up staining (''chroma'' in Greek means ''color''). Although the X chromosome could be stained just as well as the others, Henking was unsure whether it was a different class of the object and consequently named it ''X element'', which later became X chromosome after it was established that it w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenal Insufficiency
Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of steroid hormones. The adrenal glands—also referred to as the adrenal cortex—normally secrete glucocorticoids (primarily cortisol), mineralocorticoids (primarily aldosterone), and androgens. These hormones are important in regulating blood pressure, electrolytes, and metabolism as a whole. Deficiency of these hormones leads to symptoms ranging from abdominal pain, vomiting, muscle weakness and fatigue, low blood pressure, depression, mood and personality changes (in mild cases) to organ failure and shock (in severe cases). Adrenal crisis may occur if a person having adrenal insufficiency experiences stresses, such as an accident, injury, surgery, or severe infection; this is a life-threatening medical condition resulting from severe deficiency of cortisol in the body. Death may quickly follow. Adrenal insufficiency can be caused by dysfunction of the adrenal gland itself, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-linked Recessive
''Main Article'': Sex linkage X-linked recessive inheritance is a mode of Mendelian inheritance, inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be always expressed in males (who are necessarily hemizygous for the gene mutation because they have one X and one Y chromosome) and in females who are homozygous for the gene mutation (see zygosity). Females with one copy of the mutated gene are carriers. X-linked inheritance means that the gene causing the trait or the disorder is located on the X chromosome. Females have two X chromosomes while males have one X and one Y chromosome. Carrier females who have only one copy of the mutation do not usually express the phenotype, although differences in X-chromosome inactivation (known as skewed X-inactivation) can lead to varying degrees of clinical expression in carrier females, since some cells will express one X allele and some will express the other. The current estimate of sequenced X-linked genes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxisome
A peroxisome () is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen peroxide (H2O2) is then formed. Peroxisomes owe their name to hydrogen peroxide-generating and scavenging activities. They perform key roles in lipid metabolism and the redox, reduction of reactive oxygen species. Peroxisomes are involved in the catabolism of very long chain fatty acids, branched chain fatty acids, bile acid intermediates (in the liver), D-amino acids, and polyamines. Peroxisomes also play a role in the biosynthesis of plasmalogens: ether phospholipids critical for the normal function of mammalian brains and lungs. Peroxisomes contain approximately 10% of the total activity of two enzymes (Glucose-6-phosphate dehydrogenase and Phosphogluconate dehydrogenase, 6-Phosphogluconate dehydrogenase) in the pentose phosphate pathway, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very Long Chain Fatty Acids
A very-long-chain fatty acid (VLCFA) is a fatty acid with 22 or more carbons. Their biosynthesis occurs in the endoplasmic reticulum. VLCFA's can represent up to a few percent of the total fatty acid content of a cell. Unlike most fatty acids, VLCFAs are too long to be metabolized in the mitochondria, in the endoplasmic reticulum (ER) in plants and must be metabolized in peroxisomes. Certain peroxisomal disorders, such as adrenoleukodystrophy and Zellweger syndrome, can be associated with an accumulation of VLCFAs. Enzymes that produce VLCFAs are the targets of herbicides including pyroxasulfone. Major VLCFAs Some of the more common saturated VLCFAs: lignoceric acid (C24), cerotic acid (C26), montanic acid (C28), melissic acid (C30), lacceroic acid (C32), ghedoic acid (C34), and the odd-chain fatty acid ceroplastic acid (C35). Several monounsaturated VLCFAs are also known: nervonic acid (Δ15-24:1), ximenic acid (Δ17-26:1), and lumequeic acid (Δ21-30:1). See als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerotic Acid
Cerotic acid, or hexacosanoic acid, is a 26-carbon long-chain saturated fatty acid with the chemical formula . It is most commonly found in beeswax and carnauba wax. It is a white solid, although impure samples appear yellowish. The name is derived from the Latin word ''cerotus'', which in turn was derived from the Ancient Greek word κηρός (keros), meaning beeswax or honeycomb. Cerotic acid is also a type of very long chain fatty acid that is often associated with the disease adrenoleukodystrophy, which involves the excessive accumulation of unmetabolized fatty acid chains, including cerotic acid, in the peroxisome. See also *List of saturated fatty acids Saturated fatty acids are fatty acids that make up saturated fats. Straight-chain Saturated straight-chain fatty acids: Branched-chain Saturated branched-chain fatty acids: See also *List of unsaturated fatty acids *Carboxylic acid ... * Very long chain fatty acids References Fatty acids Alkanoic aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxisome
A peroxisome () is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen peroxide (H2O2) is then formed. Peroxisomes owe their name to hydrogen peroxide-generating and scavenging activities. They perform key roles in lipid metabolism and the redox, reduction of reactive oxygen species. Peroxisomes are involved in the catabolism of very long chain fatty acids, branched chain fatty acids, bile acid intermediates (in the liver), D-amino acids, and polyamines. Peroxisomes also play a role in the biosynthesis of plasmalogens: ether phospholipids critical for the normal function of mammalian brains and lungs. Peroxisomes contain approximately 10% of the total activity of two enzymes (Glucose-6-phosphate dehydrogenase and Phosphogluconate dehydrogenase, 6-Phosphogluconate dehydrogenase) in the pentose phosphate pathway, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological properties, and its behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code (its genotype) and the influence of environmental factors. Both factors may interact, further affecting the phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic. A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and again in his 1982 book '' The Extended Phenotype'' suggested that one can regard bird nests and other built structures such as caddisfly larva cases and beaver dams ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegetative State
A vegetative state (VS) or post-coma unresponsiveness (PCU) is a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness. After four weeks in a vegetative state, the patient is classified as being in a persistent vegetative state (PVS). This diagnosis is classified as a permanent vegetative state some months (three in the US and six in the UK) after a non-traumatic brain injury or one year after a traumatic injury. The term unresponsive wakefulness syndrome may be used alternatively, as "vegetative state" has some negative connotations among the public. It is occasionally also called Apallic syndrome or Apallisches syndrome, borrowings from German, primarily in European or older sources. Definition There are several definitions that vary by technical versus layman's usage. There are different legal implications in different countries. Medical definition Per the definition of the British Royal College ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Therapy
Gene therapy is Health technology, medical technology that aims to produce a therapeutic effect through the manipulation of gene expression or through altering the biological properties of living cells. The first attempt at modifying human DNA was performed in 1980, by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989. The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990. Between 1989 and December 2018, over 2,900 clinical trials were conducted, with more than half of them in Phases of clinical research, phase I. In 2003, Gendicine became the first gene therapy to receive regulatory approval. Since that time, further gene therapy drugs were approved, such as alipogene tiparvovec (2012), Strimvelis (2016), tisagenlecleucel (2017), voretigene neparvovec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
