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X-linked Spinal Muscular Atrophy Type 2
X-linked spinal muscular atrophy type 2 (SMAX2, XLSMA), also known as arthrogryposis multiplex congenita X-linked type 1 (AMCX1), is a rare neurological disorder involving death of motor neurons in the anterior horn of spinal cord resulting in generalised muscle wasting (atrophy). The disease is caused by a mutation in ''UBA1'' gene and is passed in an X-linked recessive manner by carrier mothers to affected sons. Affected babies have general muscle weakness, weak cry and floppy limbs; consequently, the condition is usually apparent at or even before birth. Symptoms resemble the more severe forms of the more common spinal muscular atrophy (SMA); however, SMAX2 is caused by a different genetic defect and only genetic testing can correctly identify the disease. The disorder is usually fatal in infancy or early childhood due to progressive respiratory failure, although survival into teenage years has been reported. As with many genetic disorders, there is no known cure to SMAX2. Appro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor Neurons
A motor neuron (or motoneuron or efferent neuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly control effector organs, mainly muscles and glands. There are two types of motor neuron – upper motor neurons and lower motor neurons. Axons from upper motor neurons synapse onto interneurons in the spinal cord and occasionally directly onto lower motor neurons. The axons from the lower motor neurons are efferent nerve fibers that carry signals from the spinal cord to the effectors. Types of lower motor neurons are alpha motor neurons, beta motor neurons, and gamma motor neurons. A single motor neuron may innervate many muscle fibres and a muscle fibre can undergo many action potentials in the time taken for a single muscle twitch. Innervation takes place at a neuromuscular junction and twitches can become superimposed as a resul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthrogryposis
Arthrogryposis (AMC) describes congenital joint contracture in two or more areas of the body. It derives its name from Greek, literally meaning "curving of joints" (', "joint"; ', late Latin form of late Greek ', "hooking"). Children born with one or more joint contractures have abnormal fibrosis of the muscle tissue causing muscle shortening, and therefore are unable to perform active extension and flexion in the affected joint or joints. AMC has been divided into three groups: amyoplasia, distal arthrogryposis, and syndromic. Amyoplasia is characterized by severe joint contractures and muscle weakness. Distal arthrogryposis mainly involves the hands and feet. Types of arthrogryposis with a primary neurological or muscle disease belong to the syndromic group. Signs and symptoms Often, every joint in a patient with arthrogryposis is affected; in 84% all limbs are involved, in 11% only the legs, and in 4% only the arms are involved. Every joint in the body, when affected, displays ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-linked Recessive Disorders
Sex linked describes the sex-specific patterns of inheritance and presentation when a gene mutation (allele) is present on a sex chromosome (allosome) rather than a non-sex chromosome (autosome). In humans, these 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 them characteristically different from autosomal dominance and recessiveness. There are many more X-linked conditions than Y-linked conditions, since humans have several times as many genes on the X chromosome than the Y chromosome. Only females are able to be carriers for X-linked conditions; males will always be affected by any X-linked condition, since they have no second X chromosome with a healthy copy of the gene. As such, X-linked recessive conditions affect males much more commonly than females. In X-linked recessive inheritance, a son born to a carrier mother and an unaffected fat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemic Atrophies Primarily Affecting The Central Nervous System
Systemic fundamental to a predominant social, economic, or political practice. This refers to: In medicine In medicine, ''systemic'' means affecting the whole body, or at least multiple organ systems. It is in contrast with ''topical'' or ''local''. * Systemic administration, a route of administration of medication so that the entire body is affected *Systemic circulation, carries oxygenated blood from the heart to the body and then returns deoxygenated blood back to the heart *Systemic disease, an illness that affects multiple organs, systems or tissues, or the entire body *Systemic effect, an adverse effect of an exposure that affects the body as a whole, rather than one part *Systemic inflammatory response syndrome, an inflammatory state affecting the whole body, frequently in response to infection *Systemic lupus erythematosus, a chronic autoimmune connective tissue disease that can affect any part of the body * Systemic scleroderma, also known as systemic sclerosis, a system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Muscular Atrophies
Spinal muscular atrophies (SMAs) are a genetically and clinically heterogeneous group of rare debilitating disorders characterised by the degeneration of lower motor neurons (neuronal cells situated in the anterior horn of the spinal cord) and subsequent atrophy (wasting) of various muscle groups in the body. While some SMAs lead to early infant death, other diseases of this group permit normal adult life with only mild weakness. Classification Based on the type of muscles affected, spinal muscular atrophies can be divided into: * ''Proximal spinal muscular atrophies'', i.e., conditions that affect primarily proximal muscles; * ''Distal spinal muscular atrophies'' (which significantly overlap with distal hereditary motor neuronopathies) where they affect primarily distal muscles. When taking into account prevalence, spinal muscular atrophies are traditionally divided into: * '' Autosomal recessive proximal spinal muscular atrophy'', responsible for 90-95% of cases and usu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastrostomy
Gastrostomy is the creation of an artificial external opening into the stomach for nutritional support or gastric decompression. Typically this would include an incision in the patient's epigastrium as part of a formal operation. It can be performed through surgical approach, percutaneous approach by interventional radiology, percutaneous endoscopic gastrostomy (PEG) or percutaneous ultrasound gastrostomy (PUG). The opening may be used for feeding, such as with a gastrostomy tube. Techniques The Stamm gastrostomy is an open technique, requiring an upper midline laparotomy and gastrotomy, with the catheter brought out in the left hypochondrium. It was first devised in 1894 by the American Gastric Surgeon, Martin Stamm (1847–1918), who was educated greatly in surgery when he visited Germany. :de:Martin Stamm See also * Enteral feeding * List of surgeries by type * Stoma (medicine) In anatomy, a stoma (plural stomata or stomas) is any opening in the body. For example, a mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feeding Tube
Eating (also known as consuming) is the ingestion of food, typically to provide a heterotrophic organism with energy and to allow for growth. Animals and other heterotrophs must eat in order to survive — carnivores eat other animals, herbivores eat plants, omnivores consume a mixture of both plant and animal matter, and detritivores eat detritus. Fungi digest organic matter outside their bodies as opposed to animals that digest their food inside their bodies. For humans, eating is an activity of daily living. Some individuals may limit their amount of nutritional intake. This may be a result of a lifestyle choice, due to hunger or famine, as part of a diet or as religious fasting. Eating practices among humans Many homes have a large kitchen area devoted to preparation of meals and food, and may have a dining room, dining hall, or another designated area for eating. Most societies also have restaurants, food courts, and food vendors so that people may eat when away ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Ventilation
Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV), is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move air into and out of the lungs, with the main goal of helping the delivery of oxygen and removal of carbon dioxide. Mechanical ventilation is used for many reasons, including to protect the airway due to mechanical or neurologic cause, to ensure adequate oxygenation, or to remove excess carbon dioxide from the lungs. Various healthcare providers are involved with the use of mechanical ventilation and people who require ventilators are typically monitored in an intensive care unit. Mechanical ventilation is termed invasive if it involves an instrument to create an airway that is placed inside the trachea. This is done through an endotracheal tube or nasotracheal tube. For non-invasive ventilation in people who are conscious, face or nasal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Muscular Atrophy
Spinal muscular atrophy (SMA) is a rare neuromuscular disorder that results in the loss of motor neurons and progressive muscle wasting. It is usually diagnosed in infancy or early childhood and if left untreated it is the most common genetic cause of infant death. It may also appear later in life and then have a milder course of the disease. The common feature is progressive weakness of voluntary muscles, with arm, leg and respiratory muscles being affected first. Associated problems may include poor head control, difficulties swallowing, scoliosis, and joint contractures. The age of onset and the severity of symptoms form the basis of the traditional classification of spinal muscular atrophy into a number of types. Spinal muscular atrophy is due to an abnormality (mutation) in the '' SMN1'' gene which encodes SMN, a protein necessary for survival of motor neurons. Loss of these neurons in the spinal cord prevents signalling between the brain and skeletal muscles. Anot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMN1
Survival of motor neuron 1 (''SMN1''), also known as component of gems 1 or ''GEMIN1'', is a gene that encodes the SMN protein in humans. Gene ''SMN1'' is the telomeric copy of the gene encoding the SMN protein; the centromeric copy is termed ''SMN2''. ''SMN1'' and ''SMN2'' are part of a 500 kbp inverted duplication on chromosome 5q13. This duplicated region contains at least four genes and repetitive elements which make it prone to rearrangements and deletions. The repetitiveness and complexity of the sequence have also caused difficulty in determining the organization of this genomic region. ''SMN1'' and ''SMN2'' are nearly identical and encode the same protein. The critical sequence difference between the two is a single nucleotide in exon 7 which is thought to be an exon splice enhancer. It is thought that gene conversion events may involve the two genes, leading to varying copy numbers of each gene. Clinical significance Mutations in ''SMN1'' are associated w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Grey Column
The anterior grey column (also called the anterior cornu, anterior horn of spinal cord, motor horn or ventral horn) is the front column of grey matter in the spinal cord. It is one of the three grey columns. The anterior grey column contains motor neurons that affect the skeletal muscles while the posterior grey column receives information regarding touch and sensation. The anterior grey column is the column where the cell bodies of alpha motor neurons are located. Structure The anterior grey column, directed forward, is broad and of a rounded or quadrangular shape. Its posterior part is termed the base, and its anterior part the head, but these are not differentiated from each other by any well-defined constriction. It is separated from the surface of the medulla spinalis by a layer of white substance which is traversed by the bundles of the anterior nerve roots. In the thoracic region, the postero-lateral part of the anterior column projects laterally as a triangular field, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptorchidism
Cryptorchidism, also known as undescended testis, is the failure of one or both testes to descend into the scrotum. The word is from Greek () 'hidden' and () 'testicle'. It is the most common birth defect of the male genital tract. About 3% of full-term and 30% of premature infant boys are born with at least one undescended testis. However, about 80% of cryptorchid testes descend by the first year of life (the majority within three months), making the true incidence of cryptorchidism around 1% overall. Cryptorchidism may develop after infancy, sometimes as late as young adulthood, but that is exceptional. Cryptorchidism is distinct from monorchism, the condition of having only one testicle. Though the condition may occur on one or both sides, it more commonly affects the right testis. A testis absent from the normal scrotal position may be: # Anywhere along the "path of descent" from high in the posterior (retroperitoneal) abdomen, just below the kidney, to the inguinal ring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
