Diagnostics cystic fibrosis

RFLPs are often a reflection of individual genetic diversity and are not related to a clinical phenotype, but occasionally they can be diagnostic of an inherited disease. This technique is relatively new yet, it has been applied to the prenatal detection of sickle cell anemia, thalassemia, phenylketonuria, a,-antitrypsin deficiency, Huntington s chorea, Duchenne muscular dystrophy, hemophilia A and B, cystic fibrosis, and several other, diseases. 

A number of clinical symptoms characterize cystic fibrosis. Predominant among these is the presence of excess sodium chloride in cystic fibrosis patient sweat. Indeed, measurement of chloride levels in sweat remains the major diagnostic indicator of this disease. Another characteristic is the production of an extremely viscous, custard-like mucus in various body glands/organs that severely compromises their function. Particularly affected are ... 

Mucolytic Adjuvant therapy for abnormal, viscid, or inspissated mucus secretions in chronic bronchopulmonary disease (chronic emphysema, emphysema with bronchitis, chronic asthmatic bronchitis, tuberculosis, bronchiectasis, primary amyloidosis of lung) acute bronchopulmonary disease (pneumonia, bronchitis, tracheobronchitis) pulmonary complications of cystic fibrosis tracheostomy care pulmonary complications associated with surgery use during anesthesia posttraumatic chest conditions atelectasis due to mucus obstruction diagnostic bronchial studies (bronchograms, bronchospirometry, bronchial wedge catheterization). 

Children with cystic fibrosis lose excessive amounts of salt in perspiration and become dehydrated readily. A salty taste of the skin and an elevated chloride concentration of sweat are traditional diagnostic symptoms.3 More serious problems arise from progressive respiratory failure and inadequate pancreatic secretion. Lung infections with Pseudomonas aeruginosa are the major cause of death. The CFTR gene is expressed in many tissues, especially those of the mucous membranes. 

Carmen is a pale 20-year-old lady. Like many cystic fibrosis patients, she was diagnosed when she was a baby her problem was suspected when she suffered repeated respiratory infections and failed to gain weight as expected. Patients with cystic fibrosis secrete a high concentration of NaCl in their sweat and this forms the basis of an early diagnostic test for the condition. 

Sweat glands have sympathetic cholinergic innervation. Patients with cystic fibrosis secrete a large amount of salt in their sweat and this forms the basis of a diagnostic test for the condition. 

The analysis of sweat for increased electrolyte concentration is used to confirm the diagnosis of cystic fibrosis (CF). CF is recognized as a syndrome with a wide spectrum of clinical presentations associated with a defect in the cystic fibrosis transmembrane conductance regulator protein (CFTR), a protein that normally regulates electrolyte transport across epithelial membranes. (For a more detailed discussion of CF, see Chapter 40.) Several hundred mutations of CFTR have been identified. Although mutational analysis is available, it is not informative in all cases, and the sweat test remains the standard for diagnostic testing. ... 

Walhs C, Leung T, Cubitt D, Reynolds A. Stool elas-tase as a diagnostic test for pancreatic function in children with cystic fibrosis. Lancet 1997 350 1001. 

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