Prather Pediatric and Allergy Center - Ask Doctor Brent

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Title: Cystis Fibrosis

Category: Child Care


Cystic fibrosis is the most common severe autosomal recessive disorder in the white population. It occurs in about one in every 25,000 live births. About one in every 25 whites is a carrier. When two carriers are married, they have a one in four chance of having a child with cystic fibrosis for every pregnancy. About eight million Americans carry the disease gene and can be diagnosed as a carrier by tests which are available. In general it is recommended that only individuals with positive family histories of cystic fibrosis be tested because of the great expense. Testing and screening for the cystic fibrosis carrier gene or any other genetic defect should ideally be accompanied by proper explanation of the results with counselling and follow-up. Unfortunately, genetic services to provide this are very limited in the United States with only about 15,000 genetic counselors for the entire nation. At present time there are only a dozen or so laboratories in the United States offering to see a carrier test. The nearest one in Louisiana is through Tulane Medical Center in New Orleans.

Once CF is diagnosed it is very treatable and controllable in most cases but there is, at present, no cure. We are hopeful that in the next several years a cure will be developed. Within just the last few years we have isolated the gene (found on the seventh chromosome) which is specific for cystic fibrosis. Perhaps through future genetic engineering we will be able to actually treat patients with cystic fibrosis through a viral type vaccine which will enter every cell in the body and reverse the abnormality of sweat chloride production, mucous gland abnormalities, pancreatic insufficiency and chronic lung disease characteristic of this disease.

The typical symptoms of cystic fibrosis are chronic productive cough (seen usually from birth and usually associated with a wheeze) and difficulty gaining weight. How the disease evolves is extremely variable, however, and some patients will be very mild and easily missed. Others will have extremely severe cases and have difficulty passing their birth weight for several weeks or months and have obvious full blown pneumonia within the first few weeks of life. Typically the cough will be spasmodic and at least occasionally be associated with choking, gagging and spitting or vomiting. Diagnosis of CF can be made conclusively with a sweat chloride test done by collecting sweat and analyzing the amount of sodium and chloride. In patients with CF, the amount of sodium and chloride is double and triple normal and clenches the diagnosis of this dread disease. Other findings on physical exam include clubbing of the fingers, barrel shaped chest and signs of poor nutrition with thin arms and legs and poor growth and weight gain. When the doctor listens to the child's chest, wheezes and crackles will usually be heard.

Therapy for cystic fibrosis is a lifelong plan and includes things such as replacing the pancreatic enzymes which the children do not produce in sufficient quantity and taking fat soluble vitamins A, D, E and K on a regular basis. Also helpful is aggressive treatment of the lungs with chest percussion or literally clapping on the chest (front and back) to help the child expectorate mucous. This is usually done after treatments with broncodilators. All this helps keep the lungs clear.

Several medications may be in order in CF therapy including continuous or intermittent antibiotics. More and more inhaled antibiotics such as Tobramycin are being used today; also inhaled or oral prednisone to decrease anti-inflammatory changes in the lungs and to increase appetite. In the near future, we will have medicines available to reverse at least part of the abnormality occurring in the glands of the body and reverse the sodium and chloride imbalance at the cellular level. One of these medicines which is being studied presently at Tulane is AT Pase. There are several other promising medicines on the drawing board which I suspect will be available within the next five to ten years.