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Cystic fibrosis (CF), also known as mucoviscidosis, is a genetic disorder that affects mostly the lungs but also the pancreas, liver, kidneys, and intestine.〔〔 Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. Other signs and symptoms include sinus infections, poor growth, fatty stool, clubbing of the finger and toes, and infertility in males among others. Different people may have different degrees of symptoms.〔 CF is inherited in an autosomal recessive manner. It is caused by the presence of mutations in both copies of the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) protein.〔 Those with a single working copy are carriers and otherwise mostly normal. CFTR is involved in production of sweat, digestive fluids, and mucus. When CFTR is not functional, secretions which are usually thin instead become thick. The condition is diagnosed by a sweat test and genetic testing.〔 Screening of infants at birth takes place in some areas of the world.〔 There is no cure for cystic fibrosis.〔 Lung infections are treated with antibiotics which may be given intravenously, inhaled, or by mouth. Sometimes the antibiotic azithromycin is used long term. Inhaled hypertonic saline and salbutamol may also be useful. Lung transplantation may be an option if lung function continues to worsen. Pancreatic enzyme replacement and fat-soluble vitamin supplementation are important, especially in the young. While not well supported by evidence, many people use airway clearance techniques such as chest physiotherapy.〔 The average life expectancy is between 37 and 50 years in the developed world. Lung problems are responsible for death in 80% of people with cystic fibrosis.〔 CF is most common among people of Northern European ancestry and affects about one out of every 3,000 newborns.〔 About one in 25 people are carriers.〔 It is least common in Africans and Asians. It was first recognized as a specific disease by Dorothy Andersen in 1938, with descriptions that fit the condition occurring at least as far back as 1595. The name ''cystic fibrosis'' refers to the characteristic fibrosis and cysts that form within the pancreas.〔 ==Signs and symptoms== The main signs and symptoms of cystic fibrosis are salty-tasting skin, poor growth, and poor weight gain despite normal food intake, accumulation of thick, sticky mucus, frequent chest infections, and coughing or shortness of breath. Males can be infertile due to congenital absence of the vas deferens. Symptoms often appear in infancy and childhood, such as bowel obstruction due to meconium ileus in newborn babies. As the children grow, they must exercise to release mucus in the alveoli. Ciliated epithelial cells in the person have a mutated protein that leads to abnormally viscous mucus production.〔 The poor growth in children typically presents as an inability to gain weight or height at the same rate as their peers and is occasionally not diagnosed until investigation is initiated for poor growth. The causes of growth failure are multifactorial and include chronic lung infection, poor absorption of nutrients through the gastrointestinal tract, and increased metabolic demand due to chronic illness.〔 In rare cases, cystic fibrosis can manifest itself as a coagulation disorder. Vitamin K is normally absorbed from breast milk, formula, and later, solid foods. This absorption is impaired in some cystic fibrosis patients. Young children are especially sensitive to vitamin K malabsorptive disorders because only a very small amount of vitamin K crosses the placenta, leaving the child with very low reserves and limited ability to absorb vitamin K from dietary sources after birth. Because factors II, VII, IX, and X (clotting factors) are vitamin K–dependent, low levels of vitamin K can result in coagulation problems. Consequently, when a child presents with unexplained bruising, a coagulation evaluation may be warranted to determine whether there is an underlying disease. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cystic fibrosis」の詳細全文を読む スポンサード リンク
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