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Ataxia Syndrome
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder A neurodegenerative disease is caused by the progressive loss of neurons, in the process known as neurodegeneration. Neuronal damage may also ultimately result in their death. Neurodegenerative diseases include amyotrophic lateral sclerosis, mul ... most frequently seen in male premutation carriers of Fragile X syndrome (FXS) over the age of 50. The main clinical features of FXTAS include Movement disorders, problems of movement with Cerebellar ataxia, cerebellar gait ataxia and action tremor. Associated features include parkinsonism, cognitive decline, and dysfunction of the autonomic nervous system. FXTAS is found in Fragile X "premutation" carriers, which is defined as a Trinucleotide repeat expansion disease, trinucleotide repeat expansion of 55-200 CGG repeats in the Fragile X mental retardation-1 (''FMR1'') gene. 4-40 CGG repeats in this gene is considered normal, while individua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fmr1
''FMR1'' (Fragile X Messenger Ribonucleoprotein 1) is a human gene that codes for a protein called ''fragile X messenger ribonucleoprotein'', or FMRP. This protein, most commonly found in the brain, is essential for normal cognitive development and female reproductive function. Mutations of this gene can lead to fragile X syndrome, intellectual disability, premature ovarian failure, autism, Parkinson's disease, developmental delays and other cognitive deficits. The FMR1 premutation is associated with a wide spectrum of clinical phenotypes that affect more than two million people worldwide. Function Synaptic plasticity FMRP has a diverse array of functions throughout different areas of the neuron; however these functions have not been fully characterized. FMRP has been suggested to play roles in nucleocytoplasmic shuttling of mRNA, dendritic mRNA localization, and synaptic protein synthesis. Studies of Fragile X syndrome have significantly aided in the understanding of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Linkage
Sex linkage describes the sex-specific patterns of inheritance and expression when a gene is present on a sex chromosome (allosome) rather than a non-sex chromosome ( autosome). Genes situated on the X-chromosome are thus termed X-linked, and are transmitted by both males and females, while genes situated on the Y-chromosome are termed Y-linked, and are transmitted by males only. As human females possess two X-chromosomes and human males possess one X-chromosome and one Y-chromosome, the phenotype of a sex-linked trait can differ between males and females due to the differential number of alleles (polymorphisms) possessed for a given gene. In humans, sex-linked patterns of inheritance are termed X-linked recessive, X-linked dominant and Y-linked. The inheritance and presentation of all three differ depending on the sex of both the parent and the child. This makes sex-linked patterns of inheritance characteristically different from autosomal dominance and recessiveness. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fragile X-associated Tremor/ataxia Syndrome
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder most frequently seen in male premutation carriers of Fragile X syndrome (FXS) over the age of 50. The main clinical features of FXTAS include problems of movement with cerebellar gait ataxia and action tremor. Associated features include parkinsonism, cognitive decline, and dysfunction of the autonomic nervous system. FXTAS is found in Fragile X "premutation" carriers, which is defined as a trinucleotide repeat expansion of 55-200 CGG repeats in the Fragile X mental retardation-1 (''FMR1'') gene. 4-40 CGG repeats in this gene is considered normal, while individual with >200 repeats have full Fragile X Syndrome. In contrast to FXS full mutation, which is diagnosed early in childhood, symptoms of FXTAS manifest in individuals over the age of 50. Like FXS, FXTAS is most common and most severe in males due to the mutation's X-linked inheritance pattern. FXTAS has an incidence of 30-40% (ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seizures
A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, or consciousness. Symptoms vary widely. Some seizures involve subtle changes, such as brief lapses in attention or awareness (as seen in absence seizures), while others cause generalized convulsions with loss of consciousness ( tonic–clonic seizures). Most seizures last less than two minutes and are followed by a postictal period of confusion, fatigue, or other symptoms. A seizure lasting longer than five minutes is a medical emergency known as status epilepticus. Seizures are classified as provoked, when triggered by a known cause such as fever, head trauma, or metabolic imbalance, or unprovoked, when no immediate trigger is identified. Recurrent unprovoked seizures define the neurological condition epilepsy. Clinical features Seizur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertension
Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. Hypertension is a major cause of premature death worldwide. High blood pressure is classified as essential hypertension, primary (essential) hypertension or secondary hypertension. About 90–95% of cases are primary, defined as high blood pressure due to non-specific lifestyle and Genetics, genetic factors. Lifestyle factors that increase the risk include excess salt in the diet, overweight, excess body weight, smoking, physical inactivity and Alcohol (drug), alcohol use. The remaining 5–10% of cases are categorized as secondary hypertension, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibromyalgia
Fibromyalgia (FM) is a functional somatic syndrome with symptoms of widespread chronic pain, accompanied by fatigue, sleep disturbance including awakening unrefreshed, and Cognitive deficit, cognitive symptoms. Other symptoms can include headaches, Abdominal pain, lower abdominal pain or cramps, and Depression (mood), depression. People with fibromyalgia can also experience insomnia and extreme sensitivity. The causes of fibromyalgia are unknown, with several pathophysiologies proposed. People with fibromyalgia are sometimes accused of imagining their symptoms. Fibromyalgia was first recognised in the 1950s, and defined in 1990, with updated criteria in 2011, 2016, and 2019. Fibromyalgia is estimated to affect 2 to 4% of the population. Women are affected more than men. Rates appear similar across areas of the world and among varied cultures. Symptoms of fibromyalgia are persistent in most patients. The treatment of fibromyalgia is Symptomatic treatment, symptomatic an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fragile X-associated Primary Ovarian Insufficiency
Fragile X-associated primary ovarian insufficiency (FXPOI) is the most common genetic cause of premature ovarian failure in women with a normal karyotype 46, XX. The expansion of a CGG repeat in the 5' untranslated region of the ''FMR1'' gene from the normal range of 5-45 repeats to the premutation range of 55-199 CGGs leads to risk of FXPOI for ovary-bearing individuals. About 1:150-1:200 women in the US population carry a premutation. Women who carry an ''FMR1'' premutation have a roughly 20% risk of being diagnosed with FXPOI, compared to 1% for the general population, and an 8-15% risk of developing the neurogenerative tremor/ataxia disorder (FXTAS). ''FMR1'' premutation women are also at increased risk of having a child with a CGG repeat that is expanded to >200 repeats (a full mutation). Individuals with a full mutation, unlike the premutation, produce little to no mRNA or protein from the ''FMR1'' gene and have fragile X syndrome as a result. Clinical diagnosis Primary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trinucleotide Repeat Expansion
A trinucleotide repeat expansion, also known as a triplet repeat expansion, is the DNA mutation responsible for causing any type of disorder categorized as a trinucleotide repeat disorder. These are labelled in dynamical genetics as dynamic mutations. Triplet expansion is caused by slippage during DNA replication, also known as "copy choice" DNA replication. Due to the repetitive nature of the DNA sequence in these regions, 'loop out' structures may form during DNA replication while maintaining complementary base pairing between the parent strand and daughter strand being synthesized. If the loop out structure is formed from the sequence on the daughter strand this will result in an increase in the number of repeats. However, if the loop out structure is formed on the parent strand, a decrease in the number of repeats occurs. It appears that expansion of these repeats is more common than reduction. Generally, the larger the expansion the more likely they are to cause disease or i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Interference
RNA interference (RNAi) is a biological process in which RNA molecules are involved in sequence-specific suppression of gene expression by double-stranded RNA, through translational or transcriptional repression. Historically, RNAi was known by other names, including ''co-suppression'', ''post-transcriptional gene silencing'' (PTGS), and ''quelling''. The detailed study of each of these seemingly different processes elucidated that the identity of these phenomena were all actually RNAi. Andrew Fire and Craig Mello shared the 2006 Nobel Prize in Physiology or Medicine for their work on RNAi in the nematode worm ''Caenorhabditis elegans'', which they published in 1998. Since the discovery of RNAi and its regulatory potentials, it has become evident that RNAi has immense potential in suppression of desired genes. RNAi is now known as precise, efficient, stable and better than antisense therapy for gene suppression. Antisense RNA produced intracellularly by an expression vector may be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Methylation
DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter (genetics), promoter, DNA methylation typically acts to repress gene Transcription (genetics), transcription. In mammals, DNA methylation is essential for normal development and is associated with a number of key processes including genomic imprinting, X-chromosome inactivation, repression of transposable elements, aging, and carcinogenesis. As of 2016, two nucleobases have been found on which natural, enzymatic DNA methylation takes place: adenine and cytosine. The modified bases are N6-methyladenine,D. B. Dunn, J. D. Smith: "The occurrence of 6-methylaminopurine in deoxyribonucleic acids". In: ''Biochem J.'' 68(4), Apr 1958, S. 627–636. [//www.ncbi.nlm.nih.gov/pubmed/13522672?dopt=Abstract PMID 13522672]. . 5-methylcytosineB. F. Vanyushin, S. G. Tkacheva, A. N. Belozers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the process of transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and the ribosome creates the protein utilizing amino acids carried by transfer RNA (tRNA). This process is known as translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of genetic information in a biological system. As in DNA, genetic inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
