Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic condition in which a female is partially or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hairline at the back of the neck, short stature, and swollen hands and feet are seen at birth. Typically, those affected do not develop menstrual periods, or breasts without hormone treatment and are unable to have children without reproductive technology. Heart defects, diabetes, and low thyroid hormone occur in the disorder more frequently than average. Most people with Turner syndrome have normal intelligence; however, many have problems with spatial visualization that may be needed in order to learn mathematics. Vision and hearing problems also occur more often than average.Turner syndrome is not usually inherited; rather, it occurs during formation of the reproductive cells in a parent or in early cell division during development. No environmental risks are known, and the mothers age does not play a role. While most people have 46 chromosomes, people with Turner syndrome usually have 45 in some or all cells. The chromosomal abnormality is often present in just some cells, in which case it is known as Turner syndrome with mosaicism. In these cases the symptoms are usually fewer, and possibly none occur at all. Diagnosis is based on physical signs and genetic testing.No cure for Turner syndrome is known. Treatment may help with symptoms. Human growth hormone injections during childhood may increase adult height.
The archetypical first clinical symptom is weakness of tail tonus that progresses to paralysis of the tail, followed by a progression up the body to affect the hind limbs and finally the forelimbs.However, similar to MS, the disease symptoms reflect the anatomical location of the inflammatory lesions, and may also include emotional lability, sensory loss, optic neuritis, difficulties with coordination and balance (ataxia), and muscle weakness and spasms. Recovery from symptoms can be complete or partial and the time varies with symptoms and disease severity. Depending on the relapse-remission intervals, rats can have up to three bouts of disease within an experimental period. In mice
Demyelination is produced by injection of brain extracts, CNS proteins (such as myelin basic protein), or peptides from such protein emulsified in an adjuvant such as complete Freunds adjuvant. The presence of the adjuvant allows the generation of inflammatory responses to the protein/peptides. In many protocols, mice are coinjected with pertussis toxin to break down the blood-brain barrier and allow immune cells access to the CNS tissue. This immunisation leads to multiple small disseminated lesions of demyelination (as well as micro-necroses) in the brain and spinal cord and the onset of clinical symptoms.Although sharing some features, mostly demyelination, this model, first introduced in the 1930s, differs from human MS in several ways. EAE either kills animals or leaves them with permanent disabilities; animals with EAE also suffer severe nerve inflammation, and the time course of EAE is entirely different from MS, being the main antigen (MBP) in charge.