Hereditary hemorrhagic telangiectasia (HHT), also known as Osler–Weber–Rendu disease and Osler–Weber–Rendu syndrome, is a rare autosomal dominant genetic disorder that leads to abnormal blood vessel formation in the skin, mucous membranes, and often in organs such as the lungs, liver, and brain.It may lead to nosebleeds, acute and chronic digestive tract bleeding, and various problems due to the involvement of other organs. Treatment focuses on reducing bleeding from blood vessel lesions, and sometimes surgery or other targeted interventions to remove arteriovenous malformations in organs. Chronic bleeding often requires iron supplements and sometimes blood transfusions. HHT is transmitted in an autosomal dominant fashion, and occurs in one in 5,000–8,000 people in North America.The disease carries the names of Sir William Osler, Henri Jules Louis Marie Rendu, and Frederick Parkes Weber, who described it in the late 19th and early 20th centuries. Signs and symptoms
Telangiectasias
Telangiectasia (small vascular malformations) may occur in the skin and mucosal linings of the nose and gastrointestinal tract. The most common problem is nosebleeds (epistaxis), which happen frequently from childhood and affect about 90–95% of people with HHT. Lesions on the skin and in the mouth bleed less often but may be considered cosmetically displeasing; they affect about 80%. The skin lesions characteristically occur on the lips, the nose and the fingers, and on the skin of the face in sun-exposed areas. They appear suddenly, with the number increasing over time.About 20% are affected by symptomatic digestive tract lesions, although a higher percentage have lesions that do not cause symptoms.
They isolate themselves from the host countrys environment, which they come to perceive as hostile, withdraw into an (often mental) "ghetto" and see return to their own culture as the only way out. This group is sometimes known as "Rejectors" and describes approximately 60% of expatriates. These "Rejectors" also have the greatest problems re-integrating back home after return. Some people integrate fully and take on all parts of the host culture while losing their original identity. This is called cultural assimilation. They normally remain in the host country forever. This group is sometimes known as "Adopters" and describes approximately 10% of immigrants. Some people manage to adapt to the aspects of the host culture they see as positive, while keeping some of their own and creating their unique blend. They have no major problems returning home or relocating elsewhere. This group can be thought to be cosmopolitan. Approximately 30% of immigrants belong to this group.Culture shock has many different effects, time spans, and degrees of severity. Many people are hampered by its presence and do not recognize why they are bothered.There is evidence to suggest that the psychological influence of culture shock might also have physiological implications. For example, the psycho-social stress experienced during these circumstances is correlated with an early onset of puberty. Transition shock
Culture shock is a subcategory of a more universal construct called transition shock. Transition shock is a state of loss and disorientation predicated by a change in ones familiar environment that requires adjustment.